The goal of ALMA is an array of 64 antennas of 12 meters diameter.
Recognizing
the increased
scientific opportunity that such an array presents over the existing MMA
and LSA
concepts, both
the U.S. MMA scientific advisory committee (the MAC) and the European
LSA scientific
advisory committee (the SAC) have consistently endorsed the merger of
the two
projects. While
each side will be entitled only to half the time on the ALMA, that half
provides a
net increase in
capability. ALMA is an example of a partnership of augmented benefit to
all
participants.
The MOU signed June 10 commits both sides to a common design and
development
phase for
ALMA. There is a stated intent of both sides to continue to the
construction phase
of ALMA,
but no such commitment to do so--at least not yet.
The MOU sets up an organization and oversight structure for ALMA.
The top level
of that
organization is the ALMA Coordination Committee (ACC), a board of twelve
members
half of
whom are European appointees and half are appointed by the NSF. Under
this Board is
the
ALMA Executive Committee (AEC)two managers from the LSA and two
from the
MMA--who
are charged with defining and managing the ALMA Design and Development
work program.
The
AEC has until October 10, 1999, to present that work plan to the ACC for
approval;
once
approved, the AEC will implement the plan. On or before May 2000 the
AEC is to
submit to the
ACC a draft of the construction and management plan for ALMA. In the
succeeding six
months
the NSF and the European institutions will negotiate their commitments
to that plan.
If all goes
well, construction will begin in 2001, just as has been planned for the
MMA with no
delay.
The U.S. side of ALMA will be the MMA Project renamed to ALMA/US but
otherwise
unchanged. In particular, ALMA/US will remain an integral facility of
the NRAO
identical in all
institutional respects to the VLA, VLBA, and the GBT. The
university-based
Millimeter Array
Development Consortium (MDC) will remain in the management structure of
ALMA/US and
will
contribute, as previously planned, throughout the development,
construction, and
operational
phase of ALMA.
R. L. Brown
The meeting will be held October 6-8 in Washington, D. C. The purpose
of the
conference will be
to highlight the science that this powerful world array will accomplish,
with
particular focus on:
It will begin with a reception and demonstration for members of
Congress in the
House Science
Committee Room of the Capitol at 5:30 p.m. Wednesday, October 6, 1999.
Lectures and posters will be presented at the Carnegie Institution of
Washington,
1600 P St. NW
on October 7 and 8. Accommodations have been arranged at the nearby Omni
Shoreham
Hotel
for the period including the nights of October 5 through October 9.
Information on reserving a
room at the special Associated Universities rate is at the web site.
The room block
will be closed
on August 20, 1999.
A press conference will begin the proceedings, to explain the world
collaboration
to the media.
This will be held in the Board Room of the Carnegie Institution of
Washington at 8
a.m. on
October 7.
The conference will be organized and hosted by Associated
Universities,
Incorporated and the
National Radio Astronomy Observatory.
Invited speakers include; Sargent, Blain, Guilloteau, Scoville,
Thornley,
Genzel*, Dutrey, Boss,
Mundy, Jewitt, van Dishoeck, Menten, Evans, Fukui, Plambeck, Andre,
Crutcher,
Yamamoto,
Olofsson, Tielens, Shu, and Millar. (*= tentative).
Science with the Atacama Large Millimeter Array will be limited to
200
participants. Information
on the conference will be posted on the Millimeter Array web
site with the
URL
http://www.mma.nra
o.edu/scienc
e/science99.html
H. A. Wootten
The transferral of the load of the reflector backup structure (BUS)
from the
temporary supports
to its permanent supports have been a long process. The contractor,
unfortunately,
prolonged the
operation when, in an effort to save time, removed the temporary
supports out of the
prescribed
sequence. This caused an unanticipated redistribution of loads, causing
some back
chord members
to bend and causing one to buckle. The contractor has since restored the
BUS to its
original
configuration, performed an engineering analysis to determine why the
failures
occurred, and
developed a procedure/method for transferring the loads, which was then
successfully
accomplished.
The shape of the structure was checked after the temporary supports
were removed,
and the
weight of the BUS was carried by the permanents. The position of the
actuators was
found to
vary by only a small amount from the dimensions measured when supported
by the
temporaries.
Installation of the Vertical Feed Arm & the Upper Feed
Arm -
The photograph in the
previous Newsletter showed the Vertical Arm complete through modules H.
Since then,
the
members of the VFA module M were bolted to the Upper Feed Arm, and the
Upper Feed
Arm
was trail assembled to the structure made up of modules K and L, on the
ground. This
trial went
well, and preparations for the lift of K and L were completed. Lifting
of modules
was delayed
while their alignment was checked and confirmed, but on June 2 the
modules were
raised into
place. Placement of the fill-in members which create the bridging module
J is
complete and their
welding is in process. The telescope is shown in the figures (as of June
10). It is
now planned to
raise the Feed/Receiver Room late in June. Beginning in mid-July, the
Upper Feed Arm
will be
raised and connected into place.
Servo - The structure was rotated in elevation for
the first
time on May 19, 1999, when it was
moved 12 degrees to position it for the installation of the middle
portion of the
Vertical Feed
Arm. This important test was carried out using the portable maintenance
unit (PMU)
to control
the elevation motion. Both motor current and voltage were monitored,
and all
movement of the
structure was smooth, silent, and without vibration. All eight
forty-horsepower
elevation motors
were used. Motor currents were predicted accurately by the analysis of
counterweight
out-of-balance and motion was readily controlled to 1/50 of an inch.
Surface Panels - Measurement of GBT panels is
continuing at the
RSI facility in Sterling, VA.
NRAO inspections are of two types. In one, surface accuracy of the
unpainted panels
is analyzed
on the basis of measurements provided by the manufacturer, and a number
of panels
selected by
NRAO from the tier under review are measured again, with NRAO witnessing
the
measurements.
If it is determined that the measurements agree with those provided by
the
manufacturer, and if
the table of measurements for the tier shows that the entire tier is
within the
accuracy specified in
the contract, then the panels of a tier are accepted. By May 25, 1188
panels (59
percent of the
total of 2,004) from 22 tiers passed this requirement. The second type
of
inspection involves
painted panels. As before, selected panels of a given tier are
inspected, and all
panels must pass
scrutiny for the tier to be accepted. For the sample selected, the paint
thickness
is measured at
many positions using a gauge provided by NRAO.
R. D. Hall and D. E Hogg
Nine of the twelve ground rangefinders were mutually scanning and
ranging to one
another. A
pair of rangefinders also ranged to a fixed target retro-reflector 1.3
km distant
from the GBT,
while a second rangefinder pair ranged to the single ball
retro-reflector mounted on
the GBT feed
arm. A complete set of range samples (AZ range pairs) was taken every
two minutes,
for a total
observation time of four hours. Temperature, barometric pressure, and
relative
humidity data
inputs from multiple stations were logged for each set of range scans.
A laser target acquisition control algorithm developed by Ramon
Creager was
operational, to
electronically locate and lock the rangefinders onto their targets
before the
evening's scans started.
The range, data, and electronic rangefinder diagnostic's data, were
logged and
plotted during the
measurement run. The diagnostic's data consist of received beam signal
intensity
and return signal
phase, and atmospheric data. A large data set was obtained, which will
be analyzed
independently
by Don Wells, and by the antenna metrology group, to obtain accurate
measurements of
rangefinder locations.
In the next two months, the last three rangefinders will become
operational,
pending running of
cables through the recently installed conduits. Additional target
retro-reflectors
will be placed on
the telescope. At that time a complete test of the ground rangefinder
metrology
system will be
conducted.
M. A. Goldman & R. H. Hall
Howard E. Tatel worked for the Carnegie Institute Department of
Terrestrial
Magnetism (DTM)
in the 1950s and collaborated with the Blaw-Knox Company of Pittsburgh
to design a
telescope
for DTM. Blaw-Knox had also received telescope orders from NRAO, the
University of
Michigan, and the Jet Propulsion Laboratory. Tatel's concept used large
diameter
gears for the
two axes to provide high precision at relatively low cost. Bob Hall, who
is now the
GBT project
manager, was then manager of the antenna division at Blaw-Knox. He
expanded Tatel's
concept,
generated a practical working design, and supervised the construction of
these
telescopes. Tatel
died on a field trip in 1957 and never saw the completion of his
telescopes. 85-1
was dedicated in
October of 1958, and named in his memory.
The telescope began continuous operation in April of 1959. Fred Crews
recalls (in
"The
Observer," March 31, 1964) that the first observations were done on
Friday,
February 13, 1959.
"Initially there were only two operators (Fred Crews and Bill Meredith),
who worked
12 hour
shifts, keeping the telescope going 24 hours a day except for weekends
when the
scientists did
their own observing."
The year 1999 is a significant 40th anniversary not only because the
Tatel
Telescope began
regular use, but also because the first scientific results were obtained
in 1959, as
a result of the
completion of the Tatel. According to the first NRAO annual report (July
1959), the
staff
astronomers in 1959 were David Heeschen and Frank Drake. (It is thus
quite
appropriate that
Frank Drake was chosen as the Jansky Lecturer for this year.) Visiting
astronomers
in 1959
included George Field, Hein Hvatum, T. K. Menon, Donald Osterbrock,
Grote Reber,
Mort
Roberts, and Gart Westerhout.
The first receivers were for bands at 440 MHz, 1.1-1.5 GHz, and 8
GHz. The
first observing
programs included studies of the planets Jupiter and Venus (Drake), the
first
detailed maps of the
Galactic center (Drake), attempts to detect 21 cm line emission in
globular clusters
(Roberts), and
multi-wavelength studies of supernova remnants (Heeschen). Menon
studied the
Cygnus loop
and the Orion nebula, Field observed Cygnus A, Heeschen surveyed spiral
and
elliptical galaxies.
Drake's famous project OZMA was started in 1959.
Today the Tatel Telescope is still in continuous use as part of the
Green Bank
Interferometer,
now funded partly by NASA for studies of x-ray and gamma-ray binary
stars.
Fred Crews concludes, in the 1964 Observer article,
"The 85 Foot Tatel
Telescope has now been
in operation for five years. Its life expectancy is 20 years." But
today, in 1999,
the telescope has
been productive for twice its expected lifetime, thanks to Howard
Tatel's initiative
and Bob Hall's
rugged design. How many of us can say the same?
F. D. Ghigo
The first attempts to use the 140 Foot for VLBI observations were in
January
1967. The first
fringes found with the 140 Foot were detected on March 5/6, 1967 with a
baseline of
650 meters
between the 140 Foot and the Tatel Telescope (85-1). These observations
used the
Mark I
recording system and 720 kbps recording onto 7-track tapes. In June
1967 the first
fringes
between the 140 Foot and an antenna at another observatory (Haystack)
were
obtained. The first
transcendental fringes were found in July 1967 using the 140 Foot and
the 26 meters
at
Hat Creek. The first intercontental fringes were found using the
140 Foot, Haystack, Hat Creek
and Onsala. The first fringes found with an antenna in Russia also used
the 140
Foot.
The 140 Foot has made many notable VLBI observations. The first real
time
fringes in VLBI
observations were found using satellite communications to relay the IF
and LO
signals between
the 140 Foot and Algonquin Radio Observatory in the mid-1970s. The 140
Foot was one
of five
telescopes dedicated to the first VLBI network organized in 1976. The
140 Foot,
Haystack, and
Hat Creek were used to make the first VLBI images of an OH maser. The
first
measurements of
pulsar parallaxes were made using the 140 Foot, Arecibo, and
Owens Valley. The
140 Foot has
recorded with nearly all types of recording systems - Mark I, Mark II,
Mark III,
VLBA, and S2
systems.
The last VLBI observations with the 140 Foot were a part of a monitoring program for source 1928+738 as a part of a network including HALCA, the Japanese Space VLBI satellite. The investigators were D. W. Murphy (JPL), J. E. Conway (Onsala), A. Polatidis (Onsala), R. A. Preston (JPL), S. J. Tingay (JPL), D. L. Jones (JPL), D. L. Meier (JPL), H. Hirabayashi (ISAS), H. Kobayashi (ISAS), and Y. Murata (ISAS).
A. H. Minter
|b| < 5, l = -15 to 255. These images have 11.17\ arcm and
7.25\ arcm
FWHM resolution at
8.35 and 14.35 GHz respectively. These observations used the NRAO/NASA
Green Bank
Earth Station to survey the sky simultaneously at these frequencies.
The first survey, GPA, covers 0.82 sr (6.5 \ %) of the sky. The
survey is
sensitive to discrete
galactic and extragalactic sources. A source list is presented for all
599 sources
brighter than
0.9 ~ Jy at 8.35 GHz or brighter than ~ 2.5 Jy at 14.35 GHz.
The FITS format images, residual
images, source lists, and archive data are all
available at http://www.gb.nrao.edu/~gla
ngsto/GPA/
.
G. I. Langston & A. T. Minter
Observatory-wide, funds in the computer budgets are tight this year.
However, we
have sufficient
resources to upgrade the main Unix server (Arcturus). In addition, we
will be able
to replace five
of the older public Suns with PCs running Linux.
The projection system in the new Green Bank auditorium is a very
flexible one
based on NTSC.
For use with today's computer graphics, however, it does not have
sufficient
resolution, as was
clear during two GBT meetings last year. We have purchased a dedicated
projector
with
improved resolution and brightness to use for computer-based
presentations.
G. C. Hunt
Once again, we worked with local seventh grade students on a six-week
astronomy
project
entitled "Our Place in the Universe." This year, all Green Bank seventh
graders
spent the night at
the Observatory conducting research projects on The 40 Foot
Telescope,
using our library and
interacting with staff astronomers. At the conclusion of their project,
they
presented their findings
during a colloquium held at the NRAO. This kind of "extended visit" by
students was
much more
popular this year. Since January 1999, nearly 700 students (from grade
5 through
undergraduate
astronomy students) have participated in research activities at the
Observatory.
In May, we began our workshop series starting with Glenville State
College
students. Preservice
teachers enrolled in the methods course at GSC spent the first week of
their
semester at the
NRAO . This field experience was essentially a compressed version of our
summer
research
institutes. Teams of students conducted research using The 40 Foot
Telescope and
interacted with
scientist "mentors" who assisted them with their projects. As the course
continued
back at the
college, students designed a classroom research project, and
field-tested it in a
K-12 classroom.
Also in May, NRAO-Green Bank hosted a three-day Chautauqua Short
Course entitled
"A Radio
View of the Universe." The Chautauqua Short Course Series is an NSF
sponsored
program
designed to update undergraduate college faculty members' knowledge in
forefront
science
research and teaching. A record 35 professors attended the course this
year. In
addition,
University of Hawaii astronomer, Gareth Wynn-Williams, led a short
course at the
Observatory
entitled "Teaching Introductory Astronomy." The two NRAO workshops are
held
back-to-back
so that participants can attend both, if desired.
The last two weeks of June brought 16 in service teachers to the
Observatory for
the "RARE
CATS" Research Institute. RARE CATS (a rather tortured acronym) stands
for Radio
Astronomy Research Enhancing Coordinated and Thematic Science, where
CATS is the
acronym
given to the new West Virginia Science Curriculum. For two weeks
participants gain
first hand
experience in conducting science research and improve their content
knowledge in
astronomy.
Project RARE CATS is a two-year summer/academic year program for
participants.
During a
second summer, participants return to Green Bank for the "Hands-On
Universe"
Technology
Institute.
Hands-On Universe (HOU) is an image processing software package that
allows
teachers and
students to analyze FITS format astronomy images. The software and
curriculum were
developed
at the Lawrence Berkeley National Laboratory, and the University of
California at
Berkeley. Two
HOU institutes are scheduled for this summer. The first of these took
place
immediately
following the June RARE CATS program. Participants in the HOU institute
obtain a
site license
for the software as well as a set of curriculum materials.
And finally, to bring you up to the present, the National Youth
Science Camp will
visit the
Observatory during the second week of July. First, a small group of
students will
camp overnight
at The 40 Foot Telescope and make observations all night long. The
entire NYSC
delegation will
visit for a tour of the GBT on July 8. This event coincides with a
visit to the
site from Senator
Robert C. Byrd (D-WV). Senator Byrd will address NRAO staff and the
Science Camp
delegation, and then join them for a tour of the GBT.
S. A. Heatherly
In June, new piggyback boards were installed on all VLA correlator
cards in order
to achieve an
expanded delay range of more than 800 microseconds for all antennas.
These boards
will enable
observing anywhere in the sky, allowing compensation for the sum of the
link delay
and the
geometric delay, which has a maximum value of approximately 670
microseconds. The
VLA
correlator has been operating with this new hardware since June 2; the
change is
completely
transparent to observers. Test observations on the VLA Pie Town
link using
all four IFs are
planned for late July and throughout August, with a goal of obtaining
some
preliminary scientific
observations before the end of A configuration in late September.
J. S. Ulvestad
We have concluded the installation of the Pentium II 400 PCs running
the Linux
operating
system. It appears that in the current year we will not be able to add
more than
one or two of
these systems. After almost one year of supporting this class of
machines we
conclude that
Pentium based PCs running Linux are a good and fast alternative to
classic
workstations.
Over the next three months we intend to start upgrading our Solaris
and Linux
operating systems.
Late this summer the AOC should begin upgrading all Linux systems to
RedHat 6.1 and
all Sparc
systems to Solaris 2.6 or 2.7. The upgrades are necessary for Y2K
compliance as
well as third
party software compatibility.
We are currently testing JOBSERVE internally at NRAO. JOBSERVE is a
utility
written in Java
by Bill Cotton. It allows preparation of VLA OBSERVE files and will
eventually
replace
OBSERVE. Advantages of JOBSERVE over old OBSERVE include its operating
system and
keyboard independence and its graphical user interface. We also intend
to add the
possibility to
create OBSERVE files for VLA observations which include the antenna at
Pie Town. We
hope
to announce the first public release of JOBSERVE later in 1999.
As part of the VLA online system upgrade and rewrite we have begun to
connect the
VLA
monitor and control system to a VME/VxWorks computer system.
Requirements documents
for
the VLA Expansion have been started, and a first draft of the computing
plan for the
VLA
Expansion has been written.
G. A. van Moorsel
| Configuration | Starting date | Ending date | Proposal Deadline |
| A | 18 Jun 1999 | 27 Sep 1999 | 1 Feb 1999 |
| BnA | 08 Oct 1999 | 25 Oct 1999 | 1 Jun 1999 |
| B | 29 Oct 1999 | 14 Feb 2000 | 1 Jun 1999 |
| CnB | 25 Feb 2000 | 14 Mar 2000 | 1 Oct 1999 |
| C | 18 Mar 2000 | 30 May 2000 | 1 Oct 1999 |
| DnC | 09 Jun 2000 | 26 Jun 2000 | 1 Feb 2000 |
| D | 30 Jun 2000 | 18 Sep 2000 | 1 Feb 2000 |
The maximum antenna separations for the four VLA configurations are:
A-36 km,
B-11 km, C-3
km, D-1 km. The BnA, CnB, and DnC configurations are the hybrid
configurations with
the long
north arm, which produce a round beam for southern sources (south of
about -15
degrees
declination) and extreme northern sources (north of about 80 degrees
declination).
| Q1 | Q2 | Q3 | Q4 | |
| 1999 | C,D | D | A | B |
| 2000 | C | C,D | D | A |
| 2001 | B | B,C | C | D |
| 2002 | A | A,B | B | C |
| 2003 | D | D,A | A,B | B |
Observers should note that some types of observations are
significantly more
difficult in daytime
than at nighttime. These include observations at 327 MHz (solar and
other
interference; disturbed
ionosphere, especially at dawn), line observations at 18 and 21 cm
(solar
interference),
polarization measurements at L band (uncertainty in ionospheric rotation
measure),
and
observations at 2 cm and shorter wavelengths in B and
A configurations
(tropospheric phase
variations, especially in summer). They should defer such observations
for a
configuration cycle to
avoid such problems. In 2000, the C configuration daytime will be
about
02h RA and the
D configuration daytime will be about 10h RA.
Time will be allocated for the VLBA on intervals approximately
corresponding to
the VLA
configurations, from those proposals in-hand at the corresponding VLA
proposal
deadline. The
VLBA spends about half of available observing time in coordinated
observations with
other
networks, with the scheduling dictated by those networks. In decreasing
order of
the time
devoted to the observations, these are HALCA space VLBI, Combined
Millimeter VLBI
Array,
Global astronomical VLBI with the EVN, and geodetic arrays coordinated
by GSFC.
Any proposal requesting NRAO antennas and antennas from two or more
institutions
affiliated
with the European VLBI network is a Global proposal, and must be sent to
the EVN
scheduler as
well as to the NRAO. VLBA proposals requesting only one EVN antenna, or
requesting
unaffiliated antennas, are handled on a bilateral basis; the proposal
should be sent
both to NRAO
and to the operating institution of the other antenna requested.
Coordination of
observations with
non-NRAO antennas, other than members of the EVN and the DSN, is the
responsibility
of the
proposer.
B. G. Clark
J. E. Hibbard
Students or their faculty advisors interested in taking advantage of
this
visiting program should
contact julvesta@nrao.edu, jwrobel@nrao.edu, or mgoss@nrao.edu.
J. M. Wrobel, J. S. Ulvestad
Beginning early in 2000, the pool of proposed observations
recommended by the
VSOP Science
Review Committee will be exhausted, although some could not be observed
until as
late as
mid-2000 due to orbit evolution. New proposals for VSOP observations
will thus be
required in
the next few months. NRAO has requested that these proposals be
submitted and
reviewed
through the same mechanism used for VLBA and global ground-based VLBI
observations,
with
all proposals requesting VLBA resources thus being reviewed jointly.
This new
procedure and
details for implementing it, are under consideration by the VSOP mission
and the
VSOP
International Steering Committee (VISC). It is hoped that a decision
can be reached
in time for
new proposals to be submitted by 1999 October 1, so that some of
these can
start being observed
by 2000 January 1. Further information will be available as soon as
possible
through the VSOP
Newsletter, the "vlbi" e-mail list, or from the undersigned.
The VSOP mission has announced a symposium on "High "Energy
Astrophysical
Phenomena
Revealed by Space-VLBI," to be held at ISAS January 19-21, 2000. The
program is
expected to
include the following topics: high brightness temperature sources;
intra-day
variables; GeV and
TeV gamma-ray sources; GHz-peaked-spectrum sources; structural changes
revealed by
monitoring; survey programs; and future prospects for Space VLBI. The
announcement,
which
includes an Expression of Interest form due by July 30, 1999 may be
accessed at URL
http://www.vsop.isas.ac
.jp/Symposiu
m.html.
J. D. Romney
The primary new service that is being offered is a complete
scheduling and
data-calibration
service, where the calibration includes all aspects of amplitude and
fringe (delay,
delay-rate, and
phase) calibration. The user would receive a complete, calibrated data
set suitable
for imaging
and self-calibration. An additional service providing the actual
imaging is also
available on
request; since the method of imaging may depend quite strongly on the
scientific
goals of a
particular project, this service will be negotiated on a case-by-case
basis.
Initially, these new services are being offered on a trial basis for
one year,
and are restricted to
relatively straightforward projects until more experience is gained in
balancing the
needs of the
users with the load on NRAO staff. The eligible projects will be
continuum
observations
including no more than ten source-frequency combinations in the
frequency range
between 1.4
and 15 GHz. The services may also be requested for observations at 22
GHz; these
requests will
be filled if the demand and the staff load permit.
Calibration and/or imaging services can be requested at the time of
proposal
submission,
preferably by checking the appropriate box on the new proposal cover
sheet
(available at
http://
info.cv.nrao
.edu/html/headquarters/vlba-gvlbi.html), by making a request
directly in the
body of the proposal, or by direct request to Jim Ulvestad at
julvesta@nrao.edu.
J. S. Ulvestad
| Date | Bands | Proposals Due |
| 09 Sep to 30 Sep 1999 | 6 cm, 5 cm?, 18 cm, UHF | 01 Feb 1999 |
| 12 Nov to 03 Dec 1999 | 6 cm?, 5 cm?, 18 cm, 1.3 cm | 01 Jun 1999 |
| 10 Feb to 02 Mar 2000 | 6 cm, 18 cm, other? | 01 Oct 1999 |
| 25 May to 15 Jun 2000 | 6 cm, 18 cm, other? | 01 Feb 1999 |
The bands above marked with a question mark have been suggested, but
the final
choice has not
yet been made.
It is recommended that proposers use a standard cover sheet for their
VLBI
proposals.
Fill-in-the-blanks TeX files are available by anonymous ftp from
ftp.cv.nrao.edu,
directory
proposal or via the VLBA home page on the web. Printed forms, for
filling in by
typewriter, are
available on request from Lori Appel, AOC, Socorro.
Any proposal requesting NRAO antennas and antennas from two or more
institutions
in the
European VLBI network constitutes a Global proposal. Global proposals
MUST reach
BOTH
Network Schedulers on or before the proposal deadline date; allow
sufficient time
for mailing. In
general, fax submissions of Global proposals will not be accepted. The
Socorro
correlator will be
used for some EVN only observations unsuitable for the Bonn correlator
until such
time that they
can be processed with the JIVE correlator. Other proposals, not in EVN
sessions,
requesting use
of the Socorro correlator must be sent to NRAO even if they do not
request the use
of NRAO
antennas; proposals for the use of the Bonn correlator must be sent to
the MPIfR if
they do not
request the use of any EVN antennas.
For Global proposals, or those to the EVN alone, send proposals to:
R. Schwartz Max Planck Institut fur Radioastronomie Auf dem Hugel 69 D 53121 Bonn, Germany
For proposals to the VLBA, or Global Network proposals, send proposals to:
Director, National Radio Astronomy Observatory 520 Edgemont Road Charlottesville, VA 22903-2475 USA.
Proposals may also be submitted electronically, in Adobe Postscript
format, to
proposevn@hp.mpifr-bonn.mpg.de or propsoc@nrao.edu, respectively. Care
should be
taken to
ensure that the Postscript files request the proper paper size.
B. G. Clark
B. G. Clark
The NRAO hosted a topical session entitled "High Angular Resolution Science with the NRAO Very Long Baseline Array" at the Centennial Meeting (30 May - 3 June 1999) of the American Astronomical Society in Chicago. This event included an all-day series of oral papers, a poster session, a press reception, press conference, and a VLBA-specific promotional display.
Throughout the AAS meeting, a specially-prepared NRAO display on the exhibit floor showcased some highlights of research done with the VLBA in its first five years of full operation. The display also emphasized the capabilities of the VLBA, as a reminder to users and hopefully as an enticement to astronomers who have not yet used the VLBA. NRAO announced new services for novice U.S. users at this meeting, and a handout provided at the display outlined those services. (See article by J. Ulvestad).
On Monday evening (May 31), AUI hosted a very successful reception for the press, in which NRAO scientists and our invited speakers for the topical session met with science journalists covering the meeting. Tuesday, June 1, saw a poster session that presented many exciting research results from the VLBA. The discussions around the posters were animated and drew many visitors and interested, non-expert VLBI users.
With so many excellent research results presented at the two VLBA sessions, NRAO hosted a press conference to highlight some of those results as well as to review the VLBA's major research accomplishments over the past several years. The geometric measurement of the distance to NGC 4258 by J. Herrnstein et al., received the most press coverage, with stories appearing in the New York Times and numerous other newspapers through wire reports by the Associated Press and Reuters. The story also appeared on numerous web news sites, including CNN and ABC.
Nearly 100 science journalists from around the world attended the AAS meeting. The press conference, and the press releases about radio astronomy research distributed by NRAO and other institutions, showed these reporters the wide range of contributions made by the VLBA and other radio telescopes to the progress of astrophysics.
On Wednesday, June 2, the oral presentations highlighted the work of eight VLBA users, including that of two graduate students and two postdoctoral fellows. The presenters were J. R. Herrnstein (NRAO), A. P. Marscher (BU), K. Blundell (Oxford), C. G. Mundell (UMd), N. Bartel (York U.), M. D. Faison (U. Wisconsin), W. F. Brisken (Princeton), and P. J. Diamond (Univ. Manchester). The presentations covered a wide range of topics, from pulsar distances to radio-quiet quasars. Two additional presentations were made by J. Ulvestad and J. Wrobel on the capabilities and the use of the VLBA. During the day, more than 100 people were in attendance at the presentations.
In all, we felt the effort to showcase the science of the VLBA and present its capabilities and usage to our AAS colleagues was quite successful; ongoing activities of this kind for the VLBA and all instruments of the NRAO will continue this effort.
M. J. Claussen and D. G. Finley
The 12 Meter Telescope will be shutdown for approximately six weeks starting on June 28th. We will follow this with an approximately three-week period of system tests before resuming regular observing. During these periods we will do a number of repair, maintenance, and upgrade tasks, which include:
Note that we are shutting the telescope down one week earlier than usual this year to accommodate the dome cover replacement project.
J. G. Mangum & T. W. Folkers
A symposium on "Imaging at Radio through Submillimeter Wavelengths" was held at the Ventana Canyon Resort in Tucson on June 6-9, 1999. This symposium brought together scientists and engineers working in the rapidly developing field of astronomical imaging at radio through submillimeter wavelengths. Topics included:
Approximately 125 scientists re resenting research institutes from at least 14 different countries attended "Imaging99". A total of 49 invited and contributed oral presentations combined with 41 poster contributions offered a plethora of scientific and technological developments. The proceedings from this conference will be published in the Astronomical Society of the Pacific (ASP) Conference Series.
J. G. Mangum
We expect to release version 1.0 of AIPS++ on CDROM in September following a final round of in-house and beta testing. The CDROM will contain installations for Linux (Red Hat 5.1, 5.2 and 6.0, SuSE 6.0), and Solaris (2.5.2 and 2.6). AIPS++ can be run from the CD, but for better performance an installation to disk is recommended. Installation is very easy and requires no special system privileges.
If you would like to receive a copy of the CDROM, please email aips2-request@nrao.edu with your name, email, and shipping address. There is no charge.
The capabilities of the package as released can be toured from the AIPS++ home page at http://aips2.nrao.edu. In brief, the package contains tools for:
Extensive and powerful scripting capabilities are available via the Glish command language. Commands may be entered both from the command line and from graphical user interfaces. Documentation and support are both available on-line.
A second release is planned for early 2000. This next version is expected to include support for VLBI processing, single dish On-The-Fly processing, more advanced interactive data editing and visualization.
T. J. Cornwell
Security - Computer and network security continues to be a major concern at the Observatory. The NRAO's computer security practices must balance the need for reasonable access by users to our computing services from outside the Observatory with the need to protect those services from willful damage by unauthorized users. In recent months, we have seen a considerable increase in the "probing" of computers and networks from outside the NRAO. These probes are often used to detect vulnerabilities in our systems' configuration. There have also been a few break-ins which briefly disrupted some of the services we provide to non-NRAO sites and had the potential for greater damage.
The Computing Council and a group of NRAO technical staff are studying ways to improve the security of the computers and networking without compromising any services that are fundamental to our role as a user facility. It is likely that some changes may be required in the ways that users at other locations connect to NRAO systems. Because many network services contain security holes which cannot always be easily fixed, any to which access from outside of the NRAO is not essential may in future be blocked, to reduce our vulnerability.
Every effort will be made to identify the impact of new security measures, and to notify users they may affect, before changes are implemented.
To reduce the risks associated with remote access, we strongly recommend, and may eventually require, the use of the secure shell ("ssh") package to replace the more common "telnet", "rlogin", and "rsh" connections between the NRAO and your home system. ssh encrypts the transmitted data, including your password, and thus hides account information from "sniffer" programs. ssh is supported at all NRAO sites. Software to make ssh connections is available for UNIX and Windows, in both free and commercial versions. We urge all NRAO users to install ssh on the computers that they will use to connect to our systems.
Computing Facilities - Budget limitations have reduced the number of workstation upgrades that we can do this year. This also applies to facilities for visiting observers. We expect to upgrade one high-end visitor workstation in Charlottesville and five older systems in the visitors' areas at Green Bank, but upgrades of the online system at the VLA and of data storage capabilities at the 12 Meter were given higher priority at the AOC and Tucson. Since most of our existing public workstations will be three years old at the end of 1999, we plan to do additional upgrades at all sites next year.
Networking - As described in the previous NRAO Newsletter, the NRAO recently received an NSF grant to upgrade our internal network. This grant will allow us to improve inter-site data exchange capabilities, and to support video- and data-conferencing connections within the NRAO and to external sites which have such equipment. It will also improve Green Bank's link to the Internet in anticipation of the increase in traffic associated with bringing the GBT on-line. Significant increases in bandwidth will be required. These enhancements are now being specified, and are expected to be in place by the Fall.
Y2K - NRAO's Year 2000 (Y2K) readiness in mission-critical areas, such as fiscal and telescope operations, and NRAO-written software such as AIPS, AIPS++, and UNIPOPS, was addressed earlier this year. The Y2K readiness of the VLA, VLBA and 12 Meter Telescopes has been verified by direct testing. We are continuing to examine potential Y2K-related problems in less critical areas, such as third-party software used regularly by NRAO employees but which would not seriously affect fundamental Observatory operations should it malfunction. A full inventory of all third-party software installed and supported by computer division staff, under both UNIX and Windows, has been carried out. A web-based search utility, including Y2K compliance information where available, has been made accessible to all NRAO sites, to allow NRAO staff to make sure that any software they depend on is included. "Time machines" whose system dates have been advanced beyond the century rollover are being used for stand-alone tests of any software packages for which significant concerns remain.
Like many organizations, the NRAO's Y2K readiness also depends on that of outside providers of supplies and services. Again like many organizations, we are finding that firm assurances from third parties about Y2K readiness are hard to come by, so some Y2K contingency plans are being made.
M. R. Milner
Linux News - One of the two remaining IBM RS/6000 AIX systems at NRAO has been recently decommissioned; it was replaced by a public Linux Intel system with dual processors, twice the memory, and more disk space (for a very small fraction of the cost of the RS/6000!). Judging by the popularity of the machine with local staff and visitors, the improvement has been much appreciated.
As the deployment of Linux/Intel systems throughout the observatory becomes more commonplace, it is important for NRAO to keep sensibly up to date with releases of the kernel and the operating system. To that end, staff in Charlottesville have tested the new 2.2 kernel, which allowed us to make early use of symmetric multi-processing and also the much desired NFS file locking. Initial results with this new kernel are very encouraging, and a standard NRAO Linux distribution based on it is currently being tested and deployed.
A new record AIPSMark was set for Intel systems with this distribution. A Pentium III 500 MHz system with 256 Megabytes of memory and a 7200 RPM EIDE disk (tuned) was used with the 15APR99 version of AIPS; the result was an impressive 17.9 AIPSMarks. This is still short of the absolute record (24.6, for a HP system); details as usual are in the benchmarking section of the AIPS web page at http://www.cv.nrao.edu/aips/.
The Year 2000 (Y2K) - In addition to the Y2K issues mentioned in the section on Observatory-wide Computing, progress has been made in Charlottesville on several fronts. At the time of writing, we have almost completed upgrading our Suns to a Y2K compliant operating system version. In addition, we have established a Y2K "war room" with several machines whose date has been advanced to beyond January 1, 2000. One of these machines (Linux) has been operating for several months already without a hitch (and has successfully run AIPS, including data transfer via FITS files to systems operating in "normal" time). A sparcstation and a Wintel PC are to be added to this list. These machines are intended for local staff to test out programs or packages of concern to them.
P. P. Murphy
The 1999 Jansky Lecture, "Progress in the Search for Extraterrestrial Intelligence," will be given by Dr. Frank Drake, currently a Research Professor at the University of California, Santa Cruz and President of the SETI Institute in Mountain View, California.
Frank Drake was one of the earliest U.S. trained radio astronomers and one of the first members of the NRAO scientific staff. While living in Green Bank 40 years ago, Drake used the 85 Foot Tatel Telescope and the 300 Foot Telescope to study the nature of planetary surfaces and atmospheres. Together with Hein Hvatum, he discovered the non thermal radiation from Jupiter's Van Allen Belts. Following a brief period at JPL, he became Director of the Arecibo Observatory where the initiated the early pulsar observations there. Before leaving Arecibo to become Dean of Science at the University of California in Santa Cruz, he was a strong proponent for the construction of a Gregorian subreflector to correct for the spherical aberration which ultimately lead to the recent major upgrade of that telescope.
Dr. Drake is well known for his work on the search for intelligent life in the universe. His Green Bank Project Ozma was the first serious attempt to detect extra terrestrial intelligence. His formulation of the number of intelligent civilizations in the galaxy, which has become known as the "Drake Equation," has been the guiding principle behind all searches for radio signals from extra terrestrial civilizations.
Dr. Drake will present the Jansky Lecture in Charlottesville on October 26, in Green Bank on October 27, in Tucson on October 29, and in Socorro on October 30. The Annual NRAO-UVA Internal Symposium will be held in Charlottesville on October 26, while the annual New Mexico Symposium will be held in Socorro on October 30.
K. I. Kellermann
A meeting on real-time computing systems at the NRAO was held at the AOC in Socorro and at the VLA Site from April 12-14, 1999. The meeting principally consisted of reports from NRAO software developers and hardware engineers, with additional contributions from non-NRAO scientists and engineers. This meeting, the first of its kind in more than ten years, was particularly timely as the observatory plans for its software contribution to the ALMA project, and prepares itself for the VLA expansion. The meeting was a success, and it is hoped that similar meetings can be held in the future. The agenda and some of the papers presented at the meeting are available at http://www.nrao.edu/Real_Time/
B.E. Glendenning