From lappel at nrao.edu Mon May 4 19:43:49 2009 From: lappel at nrao.edu (Lori Appel) Date: Mon, 04 May 2009 17:43:49 -0600 Subject: [Vlavlbausers] VLBA Astrometry Workshop - Second Announcement Message-ID: <49FF7DB5.507@aoc.nrao.edu> ************************************************************************* Second Announcement VLBA Astrometry Workshop: NEW SCIENCE ENABLED BY MICROARCSECOND ASTROMETRY 21-23 July 2009 National Radio Astronomy Observatory Pete V. Domenici Science Operations Center Socorro, New Mexico http://www.aoc.nrao.edu/events/astrometry/ ************************************************************************* NRAO will host a workshop titled "NEW SCIENCE ENABLED BY MICROARCSECOND ASTROMETRY" at the Pete V. Domenici Science Operations Center in Socorro, NM from July 21 to 23, 2009. Topics of the workshop will include: planet searches, star formation, stellar astrophysics, Galactic structure, motions of local group galaxies, black holes and neutron stars, megamasers, reference frame ties, and astrometry instrumentation. The format of the workshop will be as follows: one full day will be devoted to invited talks on a range of astrometry topics. Most of the second day will consist of break-out sessions with the aim of building new astrometry collaborations. The state of the VLBA and its ongoing sensitivity upgrade project will be described and the fundamentals of VLBI astrometry will be explained. There will also be slots for approximately 12 contributed talks (note -- this is a change since the first announcement). Please submit an abstract if you wish to talk by June 1 through the registration web page. We will let all potential speakers know if their paper has been accepted by June 15. We will also have room for about 25 posters. All poster presenters will be given up to 2 minutes to "advertise" their poster. Tentative list of invited speakers and topics: * Andreas Brunthaler -- Extra-galactic astrometry * Andy Boden -- Optical/IR interferometry * Laurent Loinard -- Astrometry to star forming regions * Steve Unwin -- SIM Lite / Space-based astrometry * Geoff Bower -- Planet searching * Jim Condon -- Megamaser cosmology project * Ken Johnston -- Reference frame ties * Mareki Honma -- Galactic structure * Hideyuki Kobayashi -- VERA * Karl Menten -- t.b.a. * Adam Deller -- Pulsar astrometry * Andy Gould -- OGLE Space at the workshop will be limited, and registration will be on a first-come-first-served basis, so please register early via the form at the conference web page. There will be a registration fee of US$120. See http://www.aoc.nrao.edu/events/astrometry/ for more details. W. Brisken and M. Claussen on behalf of the organizing committees. ********************************** Apologies if you have received this email in duplicate. From lappel at nrao.edu Fri May 15 12:11:25 2009 From: lappel at nrao.edu (Lori Appel) Date: Fri, 15 May 2009 10:11:25 -0600 Subject: [Vlavlbausers] NEWS FOR VLA/VLBA/HSA/VLBI PROPOSERS Message-ID: <4A0D942D.20305@aoc.nrao.edu> NEWS FOR VLA/VLBA/HSA/VLBI PROPOSERS, May 15, 2009 This "News" posting is also available on the web, at http://www.vla.nrao.edu/astro/guides/news/. It contains the following sections General news * Support for PhD dissertations using NRAO facilities * Large proposals News for VLA proposers * General observing capabilities for the 2009 June 1 proposal deadline * EVLA Early Science o VLA to shut down for 2 months, will return as the EVLA * EVLA impact and availability News for VLBA/HSA/VLBI proposers * Regular proposal deadline is 2009 June 1 for trimester 2009-T3 * DiFX software correlator * SCHED release * VLBI at the VLA * VLBI at the EVLA * VLBA or HSA proposals * Proposals involving the EVN ******************************************************************** 1. General news a. Support for PhD dissertations using NRAO facilities Students planning to use an NRAO telescope for their PhD dissertation (particularly if more than one proposal will be required) must submit a "Plan of Dissertation Research" of no more than 1000 words with their first proposal. This plan can be referred to in later proposals. At a minimum it should contain a thesis time line and an estimate of the level of NRAO telescope resources needed. The plan provides some assurance against a dissertation being impaired by adverse referee comments on one proposal, when the referees do not see the full scope of the project. The plan can be submitted via the NRAO Interactive Services, at http://my.nrao.edu. Proposers are reminded to prepare the plan comfortably in advance of the proposal deadline. This requirement applies to all three of the NRAO major instruments: VLA, VLBA and GBT. b. Large proposals Large proposals to use NRAO instruments will be considered at the 2009 June 1 proposal deadline, and at all subsequent proposal deadlines. There is no longer a separate call for large proposals. The definition of "large" and other policy issues relating to the submission of large proposals is described in the Large Proposal Policy, at http://www.nrao.edu/admin/do/largeprop.shtml. We particularly encourage large proposals to use the last VLA D-configuration (see News for VLA proposers and EVLA Early Science below for more details about the VLA/EVLA transition). ******************************************************************** 2. News for VLA proposers a. General observing capabilities for the 2009 June 1 proposal deadline The 2009 June 1 deadline is for the last trimester to use the VLA correlator before it is turned off and the VLA becomes the EVLA, using the WIDAR correlator. Further details of this transition are described below, under EVLA Early Science. Proposals for the DnC (scheduled between 2009 September 26 and 2009 October 11) and D configurations (scheduled between 2009 October 17 and 2010 January 11) will be considered at the June 1 deadline, along with proposals to use the reconfiguration time from the C configuration to the DnC configuration (14-25 September 2009) and the reconfiguration from the DnC to the D configuration (12-16 October 2009). Proposers are encouraged to consider proposals for projects that might fill gaps in the dynamic schedule, i.e., one or more short (1-2 hour) observations covering a variety of LSTs, but especially 0-6 hrs. Proposers are warned that the availability of day time observing will be limited due to EVLA tests and commissioning, in preparation for EVLA Early Science. The number of EVLA antennas continues to increase at a rate of one every two months. At the beginning of the D-configuration we will have 23 EVLA antennas in the array, increasing to 25 by the end of the trimester. However, the VLA correlator can handle a maximum of 22 EVLA antennas (plus all remaining VLA antennas) so the VLA will have a maximum of 25 antennas through the end of the VLA D-configuration. For the trimester under consideration we will be offering extended EVLA tuning ranges at L, C, K, Ka, and Q bands. Some of these systems are "interim", which means they use old VLA polarizers. At C-band the EVLA antennas with receivers containing the old polarizers are able to tune from 4.2 to 7.7 GHz. The ranges outside the nominal VLA frequencies for C and L bands have poor sensitivity and polarization performance, as compared with the nominal VLA frequencies. Further details of the sensitivity as a function of frequency for these bands can be found at the EVLA returns page, at http://www.vla.nrao.edu/astro/guides/evlareturn/. The numbers of receiver systems available at the beginning of the D configuration are approximately as follows: Band: L Tuning range: 1-2 GHz Number: 5(EVLA)+17(interim) Band: C Tuning range: 4-8 GHz Number: 14(EVLA)+8(interim) Band: K Tuning range: 18-26.5 GHz Number: 22 Band: Ka Tuning range: 26.5-40 GHz Number: 19 Band: Q Tuning range: 40-50 GHz Number: 25 Along with the extended tuning range systems above, all antennas will have the VLA X-band (8.0-8.8 GHz) receivers available as well. For those EVLA antennas whose receivers support the wide bandwidths it is now possible to separate the two IF pairs by 10 GHz. Revised observing and data reduction procedures are needed when using the "transition" system. These are described in some detail at the EVLA returns web page, at http://www.vla.nrao.edu/astro/guides/evlareturn/, and are outlined briefly under EVLA impact and availability (section 2c(i)) below. New EVLA antennas will not be outfitted with 12-18 GHz (U-band) receivers until the end of the construction project. By the end of the upcoming D-configuration there will be only three antennas remaining with this capability, so we will not accept any 15 GHz proposals at the 2009 June 1 proposal deadline. For continuum observations the use of EVLA antennas at 18 GHz (at the low frequency end of K-band) should be considered as an alternative to using the 15 GHz receivers. Similarly, users are reminded that no proposals for 327 MHz will be considered until we find a way to solve the problem of the incompatibility of the 327 MHz receivers with the wideband EVLA electronics, announced in the January 15 edition of the News for Proposers. The VLA D-configuration will be followed by an EVLA D-configuration using the WIDAR correlator. There will be a separate call for proposals for the EVLA D-configuration for the 2009 October 1 deadline. Proposals received in response to the 2009 June 1 proposal call will not be held over for the EVLA D-configuration. Proposal preparation and submission are via the Proposal Submission Tool at http://my.nrao.edu. Several modifications to the PST have been made and will be in place starting 12:00 EDT (noon) Friday, 15 May 2009. (See the PST Release Notes (01 June 2009) at https://safe.nrao.edu/wiki/bin/view/Software/PSTReleaseNotesJun2009 for details of recent changes.) b. EVLA Early Science We will be reversing the order of the configuration cycles from the traditional D->A->B->C->D to D->C->B->A->D, beginning at the end of the VLA D-configuration in January 2010, to facilitate correlator commissioning and early science with the EVLA. Also at the end of the VLA D-configuration we will be turning off the VLA correlator. This begins a shut-down of the array of approximately 2 months, during which we will be transferring hardware from the VLA correlator to the EVLA correlator, and commissioning the first observing modes to be offered for general use using the EVLA. At the end of this period we will begin the EVLA D-configuration. At present the usual trimester system is expected to apply, so the EVLA D-configuration is likely to be shorter than a normal D-configuration due to the shut-down. However, if demand for the preceding VLA D-configuration is light, we will make every effort to move the shut-down earlier, thus enabling an earlier start to the EVLA D-configuration. There is some flexibility in the start date of the EVLA D-configuration, although it will be no earlier than mid-January 2010. The EVLA Early Science programs were advertised in the February 2009 NRAO eNews (http://www.nrao.edu/news/newsletters/enews/enews_2_2/enews_2_2.shtml#widar). This announcement, along with descriptions of the capabilities to be offered for EVLA Early Science, are available at the EVLA Information for Astronomers web page, http://www.aoc.nrao.edu/evla/astro/. In summary, the Open Shared Risk Observing program will continue to provide access to new EVLA capabilities for the whole user community as soon as the capabilities can be supported for general use. Those expert users who are able to reside in Socorro to help with EVLA commissioning for a period of time will have access to enhanced EVLA capabilities through the Resident Shared Risk Observing program. The first call for EVLA Early Science proposals will be at the 2009 October 1 proposal deadline. c. EVLA impact and availability i. Short term (September 2009 - December 2009) At the beginning of this period there will be 23 EVLA antennas in the array. As long as we continue to use the VLA correlator, hardware limitations prevent the signals from more than 22 EVLA antennas (plus any remaining VLA antennas) from being correlated. Therefore the maximum number of antennas that can be used for science by the end of this period will be 25 (22 EVLA, 3 VLA). A subset of the final WIDAR correlator will be undergoing tests at the VLA site throughout this period, and will impact the amount of observing time available. WIDAR and other commissioning activities may also have an impact on user support available during this period. As more EVLA antennas come on line, we continue to caution that users must be very careful in setting up and reducing their data in order to obtain the best science during the transition period. Issues that are important are described in detail at the EVLA returns web page (http://www.vla.nrao.edu/astro/guides/evlareturn/). A few of the most important are summarized here: * Online Doppler tracking should be used only for projects employing only EVLA antennas. Online Doppler tracking should not be used if VLA-EVLA baselines are included in an experiment because of phase jumps on VLA-EVLA baselines introduced by the VLA Fluke synthesizers at any change in frequency or bandwidth. For the same reason, phase calibration must be included at any frequency or bandwidth change for observations using both VLA and EVLA antennas. * The use of narrow-bandwidth modes on EVLA-EVLA baselines is compromised by the aliasing of emission outside the band as described on the EVLA returns web page. Please consult this web page for latest information on post-processing compensation for the aliasing effect. This problem will go away once the WIDAR correlator is used for all antennas. * Some on-line flagging issues remain. In particular, there are some cases in which the first few records of a scan are actually data from the previous scan, but are not flagged by the online system. In addition, the first 10-20 seconds after a change of band is often bad and not flagged. Users should make sure to observe a calibration source after a band change. The origins of the problems are known, and software changes are underway to eliminate them. Until those software changes occur - and are tested - users should critically examine their data to find and flag such problems. The installation and testing of S-band (2-4 GHz) receivers has begun on the EVLA. S-band receivers will be available for shared-risk observing when at least 5 have been commissioned, currently expected in late 2009. ii. Medium term (January 2010 - December 2010) The transition from the VLA correlator to the EVLA correlator is currently planned to take place in January 2010, at the end of the VLA D-configuration, as described under EVLA Early Science above. At that time the VLA will remain in the D configuration for a further trimester and the order of the configuration cycle will change to D->C->B->A. Shared-risk observing with the new WIDAR correlator will begin with the EVLA in the D-configuration. Capabilities of the new correlator will be announced in NRAO eNews and via the "News for Proposers" prior to the 2009 Oct 1 deadline. Any remaining VLA antennas will be decommissioned at the same time that the VLA correlator is turned off, and will no longer be used for astronomy until they have been retrofitted to the EVLA design. The primary antenna retrofits will be completed in mid-2010, although not all the frequency bands will be installed on all antennas. The wide-band Q, Ka, K, and C band receiver systems are expected to be completed by the end of 2010. iii. Long term (2011 - 2012) The fast samplers needed to access the full 8 GHz of bandwidth at high frequencies will be installed in all antennas by the end of 2010, and access to the wide bandwidths for general use is expected in 2012. The remaining receiver bands will be completed by Q4, 2012. ******************************************************************** 3. News for VLBA/HSA/VLBI proposers a. Proposal deadline is 2009 June 1 for trimester 2009-T3 This deadline applies to regular observing proposals requesting * the Very Long Baseline Array (VLBA), alone or with affiliate(s) http://www.vlba.nrao.edu/astro/ * the High Sensitivity Array(HSA) http://www.nrao.edu/HSA/ * the European VLBI Network(EVN) http://www.evlbi.org/ * Global cm VLBI (EVN+VLBA) in the Oct/Nov session This deadline also applies to large observing proposals requesting the VLBA, alone or with other NRAO resources. http://www.nrao.edu/administration/directors_office/largeprop.shtml The observing period is 2009 mid-September through 2010 mid-January. b. DiFX software correlator By the end of this year we expect to replace the original, hardware-based VLBA correlator with the new, software-based VLBA-DiFX system that has been under development for several years. This transition should have no impact on observations already approved, and will not occur until we are reasonably certain this statement will be true. After the transition, we will issue a call for immediate Exploratory Proposals for observations that can scientifically exploit these two extended capabilities supported by DiFX: * High spectral resolution, up to 32768 spectral points. * Extremely short integration intervals, in principle as short as a single FFT interval (equal to the number of spectral points divided by the baseband bandwidth, for Nyquist sampling). c. SCHED release Version 8.1 of SCHED was released on 2009 Feb 24; please http://www.vlba.nrao.edu/astro/#D5 for further information. Users are encouraged to employ the latest version when scheduling projects. During 2010 there are expected to be very significant changes in the hardware at the stations as the digital backends are implemented. During this period, it will be especially important to keep the scheduling software up-to-date. Also, the new software correlator, DiFX, will be controlled directly from project VEX files (.skd files). The new version of SCHED produces VEX files by default for all projects, not just projects that have Field System controlled stations. d. VLBI at the VLA VLBI at the VLA is expected to continue working well through 2009. Proposers should be careful about scheduling untested modes, particularly those using EVLA frequencies and 512 Mbps. Problems with the transfer of amplitude calibration for the phased VLA have been solved and the attached calibration information for the VLA can be used without alteration. e. VLBI at the EVLA There will be an interval of two months, beginning in 2010 Jan, during which the array will be unavailable due to the replacement of the VLA correlator with the WIDAR correlator. The array will resume operation as the EVLA with the WIDAR correlator without VLBI capabilities. Although it is expected that WIDAR commissioning will eventually include VLBI capabilities, no definite timescale for implementing this has yet been set. f. VLBA or HSA proposals Proposal preparation and submission are via the NRAO Interactive Services, http://my.nrao.edu/. g. Proposals involving the EVN For all classes of proposals involving the EVN, only the on-line tool NorthStar (http://proposal.jive.nl) should be used to prepare and submit proposals. This includes Global cm VLBI (EVN+VLBA) proposals.