ABSTRACTS OF TALKS:

The Chemical Inventory of Interstellar Clouds

Jan M. Hollis (NASA’s GSFC), Anthony J. Remijan (NRAO), & Phillip R. Jewell (NRAO)

We propose to conduct an in-depth spectral line survey of Sgr B2(N), a high-mass star-forming region rich in biomolecules, and TMC-1, a hydrocarbon-rich dark cloud region, with the Green Bank Telescope (GBT) from 150 MHz to 50 GHz. Previous spectral line surveys have been limited because they were cursory in nature, affording only a very general overview of these two prototypical spectral line sources.

In this legacy project, we intend to perform a deep survey down to an rms ~2 mK noise level that will produce databases for the identifications of weak transitions of known interstellar molecules and for the likely identification of new, but weak interstellar species. Furthermore, this survey will unambiguously identify regions of weak RFI that may not have been detected previously. All survey data will be made available to the astronomical community via a new self-contained Spectral Line Search Engine (SLiSE)—a java-based, computer-independent applet—that will allow the user to search the survey databases for frequencies or passbands of interest. SLiSE and these databases can either be web-based or, alternatively, downloaded for use on a personal machine. This legacy information would be helpful for future GBT and ALMA proposals and SLiSE could be implemented in the proposal submission tool (PST) so that users can 1) avoid overlaps with other proposals, 2) investigate passbands already observed, and 3) identify any contamination from known interstellar molecules or RFI that may interfere with their observations and thereby reducing the already large oversubscription of these areas of interest. A SLiSE demonstration will be part of the oral presentation.

Rapidly Varying Flux Densities: the Role of Scintillation

Jean-Pierre Macquart (NRAO), Barney Rickett (UCSD), Dave Jauncey (ATNF), Jim Lovell (CSIRO), Hayley Bignall (JIVE), Lucyna Kedziora-Chudczer (U. Sydney), Roopesh Ojha (USNO), Tapio Pursimo (Nordic Optical Telescope, Spain)

There are a number of potential benefits in designing any legacy variability survey so that it is sensitive to the variability caused by Interstellar Scintillation (ISS) as well as by intrinsic causes. The most obvious is that ISS gives a measure of compact source structure, rather like the output from a high-pass filter. One can estimate the angular size of sources that vary on a timescale less than T hrs as smaller than ~ 1.2 T D_kpc^-1 microas in size, where D_kpc ~ 0.1-1 for extragalactic sources and D_kpc is approximated by the source distance if it is within the Galaxy. Hence ISS gives an effective resolution in the range 10-100 microas.

We point out several instances in which this diagnostic would be useful. For example, ISS can be used to identify the presence of ultra-compact (AGN-like) cores in high-redshift galaxies, and to distinguish between pulsars/RRATs and other Galactic objects, which are unresolved by the VLA.

We also discuss cases in which ISS has played an important role in identifying the underlying physics of newly discovered sources (e.g. in the first millisecond pulsar and in the afterglows of GRBs).

The VLA’s unmatched ability to provide reliable, high precision flux density measurements makes it critical to all future large-scale variability surveys. Among the 710 flat/inverted compact extragalactic sources monitored in the MASIV survey, 30% exhibited ISS in one or more of the four epochs. These ISS time scales were from one to 3 or more days, which highlights the need for longer time-series observations to properly quantify these stochastic variations. Repeated series of observations to fainter flux densities are essential steps for future programs and should be integrated into legacy projects on variability.

Allen Telescope Array Five Gigahertz Sky Survey Geoffrey Bower (Berkeley)

One of the first scientific goals of the ATA is the Five Gigahertz Sky Survey (FiGSS). We will survey radio continuum at 5 GHz to a detection threshold of 3 mJy over 10,000 square degrees at a resolution of 1 arcmin. Matching sources with NVSS will provide spectral indices for nearly all of the 250,000 FiGSS sources. These spectral indices will be critical in separating thermal and nonthermal emission in extragalactic sources. We will survey two smaller fields to greater depth: 100 square degrees to 1 mJy and 10 square degrees to 0.3 mJy. The survey will be conducted in a mode that is sensitive to transients. The 10 square degree field will be surveyed daily, the 100 square degree field will be surveyed every 10 days, and the 104 square degree field will be surveyed 3 times.

Past Legacy: The VLA Archive Image Pilot Project Lorant Sjouwerman (NRAO)

I will present the first results of the NVAS, the NRAO VLA Archive Survey, including a demo.

Obtaining e-MERLIN Data in Conjunction With NRAO Legacy Projects Tom Muxlow (MERLIN/VLBI National Facility, Jodrell Bank Observatory)

It is intended that a form of enhanced ‘Key Program’ will be available for early e-MERLIN observing sessions. This is a new catagory of project which will allow consortia to bid for substantial amount of time on e-MERLIN. Consortia proposing for NRAO Legacy Projects may wish to make use of such programs in order to obtain complementary e-MERLIN observations.

Lessons Learned from EVLA-II Bruce Balick (U. of Washington)

The Large Synoptic Survey Telescope Philip Pinto (U. of Arizona)

AGN from the 13H XMM/Chandra deep radio/X-ray survey Nick Seymour (Spitzer Science Center), Ian McHardy (Southampton), Derek Moss (Southampton), Tom Dwelly (Southampton), Matthew Page (MSSL/UCL), & George Rieke (Arizona)

Although there is strong evidence theoretically and observationally that star-forming galaxies begin to dominate the very faintest radio source counts, AGN are still expected in many numbers below 1mJy. Even the deepest radio surveys cannot detect star-forming galaxies beyond z~1 and so the 20% of optically unidentified radio sources from these surveys are likely to include many AGN. To study this population we have observed the 13H XMM/Chandra field with the VLA (1.4 GHz) and GMRT (610 MHz) to detection limits of 30 uJy and 100 uJy respectively as radio spectra are a strong diagnostic of the underlying physics, eg ultra steep spectra are often indicative of distant, z>3, radio galaxies. This field has also been observed with the IRAC and MIPS instruments onboard Spitzer as part of a GTO survey. These data will help identify the optically faint radio sources and cover the wavelength range where these objects emit most of their energy. Currently the 15 sources spectroscopically identified above z=1 are X-ray unobscured, broad emission line QSOs, the sources you would expect from optical selection. The combination of radio spectra and MIR data is crucial in understanding the optically faintest radio sources. Here we present the latest results of our work.

An Update from the COSMOS Survey Chris Carilli (NRAO)

Deep Field Surveys with the VLA: The CDFS and UDF Ken Kellermann (NRAO)

For more than 15 years we have been using the VLA to extend our knowledge of the radio source population to microjansky levels in an attempt to better understand the relation between gravity powered (quasars, AGN, and black holes) and nuclear powered (star formation) activity and their dependence on cosmic time. Fields studied include the HDFN, SSA 13, the CDFS, and the UDF and are the result of collaborations among scientists and students at NRAO, AZ, Haveford, UVA, Jodrell Bank, ESO, MPIfEP, INAF (Trieste), STScI,, John Hopkins, IoA (Hawaii), Wisconsin, and Talladega College. We will report on some results from our recent multiwavelength study of the CDFS and the UDF, the dissemination of data, and plans for the future, along with an outline of the new techniques that were developed to minimize the effect of instrumental artifacts due to “strong” millijansky within the field.

The MOJAVE Program: Investigating Relativistic Jets in AGN

Matt Lister (Purdue University)

MOJAVE (Monitoring of Jets in AGN with VLBA Experiments) is a “Large” VLBA program to study the structure and evolution of the brightest AGN jets in the sky as seen by the VLBA at 15 GHz. The first observational phase lasted from May 2002 to December 2005, and obtained milliarcsecond-resolution linear and circular polarization images of a complete sample of 133 blazars at multiple epochs (typically 4-6) for each source. The online archive from our project (http://www.physics.purdue.edu/astro/MOJAVE) is the largest publically available collection of fully calibrated visibility data and images from the VLBA. We report results on the kinematic analysis currently underway, including the discovery of fast superluminal motions (>30 c) and curved trajectories in select sources, and first ever determination of jet speeds in over 40 blazars. We also discuss the second phase of MOJAVE, which is currently obtaining multi-frequency VLBA polarimetric images at 8.1, 8.4, 12.1 and 15.3 GHz of an extended sample of 191 AGN that includes all currently known gamma-ray blazars, 18 gigahertz-peaked spectrum sources, and 34 radio galaxies. These new data are being used to investigate Faraday rotation, de-polarization, and spectral index gradients in parsec-scale radio jets..

The Megamaser Cosmology Project James Braatz (NRAO), James Condon (NRAO), Fred Lo (NRAO), Lincoln Greenhill (CfA), Mark Reid (CfA), & Christian Henkel (MPIfR)

The standard model of cosmology consists of a flat universe composed of baryons, Dark Matter, and Dark Energy. The model is set largely by an analysis of fluctuations in the Cosmic Microwave Background. Dark Energy dominates the mass budget and causes the expansion of the universe to accelerate, yet almost nothing is known about its nature. The most valuable complement to CMB probes in constraining the equation of state of Dark Energy would be a determination of the Hubble constant to < 3%. One promising approach to measuring the Hubble constant with such precision involves distance determinations using the H₂O megamaser technique pioneered on NGC 4258. The Megamaser Cosmology Project (MCP) is a proposed Key Project aiming to measure the Hubble Constant with such precision. We will present recent progress from pilot programs, and discuss resources required from NRAO in order to complete this ambitious program.

The VLBA Imaging and Polarimetry Survey (VIPS) and GLAST Greg Taylor (UNM), Joe Helmboldt (UNM), Chris Fassnacht (UCD, NASA GSFC), Neil Gehrels (UCD, NASA GSFC), Jim Ulvestad (NRAO), Craig Walker (NRAO), Tim Pearson (Caltech), Tony Readhead (Caltech), Roger Romani (Stanford/KIPAC), Peter Michelson (Stanford/KIPAC), & Roger Blandford (Stanford/KIPAC)

The VLBA Imaging and Polarization Survey (VIPS) is a combined 5 GHz and 15 GHz survey with the Very Long Baseline Array of 1169 active galactic nuclei (AGN) with full polarization and high dynamic range. The parent sample is the CLASS survey in the region covered by the Sloan Digital Sky Survey in order to facilitate multi-wavelength science. In the first stage of the VIPS sample, being observed in 2006, all 974 new sources are being observed at 5 GHz to a noise limit of ~0.25 mJy/beam. These will be combined with observations from the CJ surveys to form a complete sample of 1169 sources with similar sensitivity and high dynamic range. A campaign to obtain redshifts is well underway using the Hobby-Eberly Telescope, the Palomar 5m, and Keck. A proposal to follow-up all resolved sources (about half) with the VLBA at 5, 8 and 15 GHz is in preparation. With this set of data it will be possible to study magnetic field launching of jets through Faraday rotation, to study AGN evolution, and to study the statistical properties of gamma-ray blazars for comparison with measurements by the Gamma-Ray Large Area Space Telescope (GLAST). The VIPS survey will compile a wealth of information about gamma-ray blazars, including estimates of Lorentz factors, which should greatly assist in designing VLBI campaigns during the period beginning in late 2007 when GLAST is operational. In this way we can make the best use of the investment in GLAST. VIPS will also stand alone as the largest VLBI imaging survey to date by a factor of 3 and the only substantial survey to employ multi-frequency polarimetry.

Transient Sources Shri Kulkarni (Caltech)

Pulsars Jim Cordes (Cornell)

Galactic Astronomy Naomi McClure-Griffiths (CSIRO, ATNF)

High-Redshift Galaxies Rob Ivison (ROE)

Legacy Projects: Lessons Learned Tom Soifer (Caltech and the Spitzer Science Center)

The Spitzer Legacy Program began with 6 projects that were allocated a total of roughly 1/2 year of observing time in the first year of Spitzer Science operations. It has continued with substantial allocations in GO Cycles 2 and beyond. This has proven to be an extremely effective means of delivering large quantities of non-proprietary data to the astronomical community, with PI groups committed to delivering extensive post-pipeline processed "data products" for public use.

In this talk, I will describe the key elements of the Spitzer Legacy program, the advantages and disadvantages for the PI teams and the astronomical community of such efforts, and what the Spitzer experience might hold for similar efforts with other major observatories.

ABSTRACTS OF POSTERS:

Early Results from GLIMPSE

GLIMPSE Team

The Galactic Legacy Infrared Mid-Plane Survey Extrodinare (GLIMPSE) has imaged the Galactic plane at longitudes 10-65 degrees on either side of the Galactic center and at latitudes |b| < 1 degree. GLIMPSE uses all four bands of the Infrared Array Camera (IRAC) on the Spitzer Space Telescope to provide a mosaiced image atlas with a spatial resolution of ~2” as well as a point source catalog and 5-sigma point source archive. The GLIMPSE project has provided us with a new view of the Milky Way. We will show examples of some its main results, among which are: the detection of the central bar in the Galaxy and determination of its radius and orientation; the location and number of spiral arms in the inner Galaxy; the stellar scale length of the Galaxy; a catalog of over 300 dust bubbles apparently blown by stellar winds from massive stars or clusters; large numbers of infrared dark clouds that are opaque at 8 microns; identification of large numbers of jets and out flows from YSOs from shocked CO or molecular hydrogen seen only in the 4.5 micron band; and determination of the NIR-MIR extinction law. The GLIMPSE data base is a rich public resource whose potential for contributing to a very wide range of science has barely been tapped.

The CORNISH Survey

The CORNISH Team

The forthcoming 'Co-ordinated Radio and Infrared Survey for High-Mass Star Formation' or CORNISH survey is described. This is a 5 GHz B configuration VLA continuum survey of the area of the northern galactic plane covered by the mid-IR SPITZER GLIMPSE survey. The survey strategy is described and some example results from a pilot region presented. Where this high spatial resolution survey complements other surveys of the plane is outlined. Primarily motivated by studies of high mass star formation, this survey will also provide a database for studies of evolved, active and binary stars, rare objects and have good legacy value for galactic studies.

Legacy Surveys with the JCMT: The SCUBA2/HARP Local Star Formation Survey James Di Francesco (National Research Council of Canada), Doug Johnstone (National Research Council of Canada), Derek Ward-Thompson (Cardiff University), Jennifer Hatchell (University of Exeter), Michiel Hogerheijde (Leiden Observatory), & Brenda Matthews (National Research Council of Canada)

The JCMT Legacy survey of Local Star Formation will map with SCUBA2 almost all star-forming regions within 0.5 kpc that are accessible by the JCMT. Most of these locations are associated with Gould’s Belt and include many well-known low-mass and intermediate-mass regions. From these observations, we will produce a flux-limited snapshot of star formation near the Sun, providing a legacy of images, as well as point-source and extended-source catalogues over almost 700 square degrees of sky. Towards the regions surveyed by SCUBA2, the survey will be sensitive to every Class 0 & I protostar and every L1544-like prestellar core within 0.5 kpc. This will be the first such catalogue that has been selected by submillimetre continuum emission, and will take the number of such known sources from tens to thousands. We will also obtain HARPB maps, in three CO isotopomers, of hundreds of the brightest sources in order to distinguish between protostellar and prestellar cores, determine outflow characteristics, and probe the kinematic and density properties of the sources in a uniform manner. We will also map the brightest sources with the SCUBA2 polarimeter, producing the first statistically significant set of polarization maps in the submillimetre. The continuum, line, and polarization images, along with the source catalogues, will be a powerful reference set for astronomers for years to come, providing a detailed Legacy Archive for future telescopes including ALMA, Herschel, JWST and beyond.

The science questions that this survey will address directly are fundamental to star formation studies. What are the relative timescales of each of the protostellar stages? How does protostellar collapse proceed? What determines the stellar initial mass function (IMF)? How does environment influence protostar formation? How do brown dwarfs form? What is the detailed spatial and velocity structure of the molecular clouds in which star formation occurs? What is the relative importance of magnetic fields and turbulence in providing cloud support? By answering or constraining these vital questions, the immediate impact of this survey will be immense and the JCMT legacy secure.

The JCMT Local Star Formation Legacy Survey consists of fifty team members from Canada, the United Kingdom, and the Netherlands.

The WISE Mission Andrew Blain (Caltech) and the WISE science team

WISE is a NASA MIDEX mission intended to survey the sky in 4 bands from 3.3 to 23 microns. Approximately 3-4 orders of magnitude more sensitive than IRAS, WISE will provide a vital backdrop for future investigations of galactic and extragalactic targets, including transients. The atlas of galaxies generated can be sifted in color space to highlight different classes, and prioritize them for follow-up studies of the astrophysics of the gas and ISM using GBT, VLA and perhaps most especially ALMA. A sample of millions of high-redshift ultraluminous galaxies visible by ALMA will allow the environmental context and range of properties of the top end of the galaxy luminosity function to be revealed, directly at the epoch when both stars in galaxies and supermassive black holes are growing and forming most actively.

The Chemical Inventory of Interstellar Clouds Jan M. Hollis (NASA’s GSFC), Anthony J. Remijan (NRAO), & Phillip R. Jewell (NRAO)

We propose to conduct an in-depth spectral line survey of Sgr B2(N), a high-mass star-forming region rich in biomolecules, and TMC-1, a hydrocarbon-rich dark cloud region, with the Green Bank Telescope (GBT) from 150 MHz to 50 GHz. Previous spectral line surveys have been limited because they were cursory in nature, affording only a very general overview of these two prototypical spectral line sources.

In this legacy project, we intend to perform a deep survey down to an rms ~ 2 mK noise level that will produce databases for the identifications of weak transitions of known interstellar molecules and for the likely identification of new, but weak interstellar species. Furthermore, this survey will unambiguously identify regions of weak RFI that may not have been detected previously. All survey data will be made available to the astronomical community via a new self-contained Spectral Line Search Engine (SLiSE)—a java-based, computer-independent applet—that will allow the user to search the survey databases for frequencies or passbands of interest. SLiSE and these databases can either be web-based or, alternatively, downloaded for use on a personal machine. This legacy information would be helpful for future GBT and ALMA proposals and SLiSE could be implemented in the proposal submission tool (PST) so that users can 1) avoid overlaps with other proposals, 2) investigate passbands already observed, and 3) identify any contamination from known interstellar molecules or RFI that may interfere with their observations and thereby reducing the already large oversubscription of these areas of interest. A SLiSE demonstration will be part of the oral presentation.

4.8 and 8.6 GHz Surveys of the Magellanic Clouds John Dickel (University of New Mexico), Vincent McIntyre (Australia Telescope National Facility), Robert Gruendl (University of Illinois), Doug Milne (Australia Telescope National Facility), & Shaun Amy (Australia Telescope National Facility)

Detailed radio images of both the Large and Small Magellanic Clouds with half-power beamwidths of 33” at 4.8 GHZ and 20” at 8.6 GHz have been obtained with the Australia Telescope Compact Array. This survey involved thousands of mosaic positions to cover a 36 square degree area toward the LMC and 20.25 square degrees toward the SMC. Full polarimetric observations were made. These images have sufficient spatial resolution (~ 8 pc at 4.8 GHz and 5 pc at 8.6 GHz) and sensitivity (3 sigma of 1 mJy/beam) to identify most of the individual supernova remnants and H II regions and also, in combination with available images from the Parkes 64-m telescope, the structure of the smooth emission from the galaxies. In addition, limited data from the sixth antenna at 4.5 - 6 km baselines are available to distinguish bright point sources (< 3”) and to help estimate sizes of individual sources smaller than the resolution of the full array. The resulting database is valuable for statistical studies and comparison with X-ray, optical, infrared, and radio spectral-line studies with similar resolution.

The VLBA Imaging and Polarization Survey: First Results Joe Helmboldt (UNM) & Greg Taylor (UNM)

The VLBA Imaging and Polarization Survey (VIPS) is an ongoing VLBI survey of ~1,100 sources selected from the Cosmic Lens All-Sky Survey (CLASS) within the survey area of the Sloan Digital Sky Survey (SDSS). We are currently obtaining 5 GHz VLBA imaging and polarization data for all sources brighter than 80 mJy. With this data, we will be able to identify candidate Compact Symmetric Objects (CSOs) and Supermassive Black Hole Binary (SBHB) candidates for follow-up observations in other bands (e.g. 8 and 15 GHz) and at different epochs. The images and polarization data will also provide a powerful tool for statistically exploring the nature of jets in these objects, especially when the data is combined with gamma-ray observations that will be obtained with the Gamma-ray Large Area Space Telescope (GLAST) that will be launched in 2007. To date, 5 GHz VLBA observations have been completed for 486 sources; the data for 378 of these sources have been correlated and reduced and are available on the web. We present preliminary results based on this data, namely the Stokes I images and polarization maps for examples of different categories of objects.

The VLA Low-frequency Sky Survey Wendy Lane (NRL), Aaron Cohen (NRL), Rick Perley (NRAO), Bill Cotton (NRAO), Jim Condon (NRAO), Namir Kassim (NRL) , T.J.W. Lazio (NRL), & Bill Erickson (Univ. of Tasmania)

We present an overview of the ongoing VLA Low-frequency Sky Survey (VLSS). The VLSS will map an area of 9.1 sr covering the entire sky above a declination of -30 degrees (or 75% of the full sky), at a frequency of 74 MHz (4 meter wavelength). It has 80 arcsec resolution and an average 5-sigma detection limit of 0.5 Jy/beam; in areas near the Galactic plane and very bright sources the noise levels will be higher. Principal data products include a set of publicly available images and a source catalog on our website (URL:http://lwa.nrl.navy.mil/VLSS). The survey is now about 90% complete, and has used about 750 hours of VLA time in the B and BnA configurations. We hope to complete most of the remaining observations in the upcoming 2006 B and BnA configurations. The catalogs and images provide an online virtual observatory at this previously unexplored frequency and complement other major surveys at higher frequencies such as the NVSS. From these data, statistically useful samples of extra-galactic and Galactic objects, such as high redshift radio galaxies, galaxy clusters, supernova remnants and pulsars can be assembled for further study. In addition, this survey will provide a crucial calibration grid for use with next-generation of large low frequency telescopes such as the Long Wavelength Array (LWA) and Low Frequency Array (LOFAR).

Legacy Projects with the Green Bank Telescope Felix J. Lockman (NRAO), Brian Mason (NRAO), & Richard Prestage (NRAO)

The Green Bank Telescope is a sensitive, versatile instrument for legacy science. It has useful performance from the FM band to 50 GHz at present, and potential for operations in the 3mm band. Its focal plane is large and can house a variety of instruments. Its optics can easily support conventional focal plane arrays at wavelengths shorter than 6 cm. This poster describes the detailed capabilities of the GBT for legacy science and gives brief examples of the kinds of experiments which might be considered. There will be space on the poster for anyone to contribute ideas for large GBT projects or to expand or comment on those already listed. We are in the process of developing plans for GBT instrumentation for the next 5 years, and will be discussing these at a Green Bank Workshop on GBT Future Instrumentation to be held September 7-8, 2006.

Investigating the Chemistry and Structure of IRAS 16293-2422: A Sun-like Protostellar System Anthony Remijan (NRAO), Mike Hollis (NASA’s GSFC), Frank Lovas (NIST ), Cecilia Ceccarelli (Laboratoire d’Astrophysique de l’Observatoire de Grenoble), & Laurent Wiesenfeld (Laboratoire d’Astrophysique de l’Observatoire de Grenoble)

We propose to conduct a 1 to 50 GHz spectral line survey with the EVLA of IRAS16293-2422, a low-mass star-forming region in the Rho Ophiuchus complex at a heliocentric distance of ~120pc. Early investigations of this source indicated a system dominated by two objects believed to be Class 0 sources, i.e. in the first phases of protostar evolution. Recent observations suggest that the system probably contains more than two objects and is considered to be a prototype for the study of chemistry in Sun-like protostars. IRAS16293-2422 is indeed the first low-mass source reported to contain “hot corinos” that are analogous to hot cores reported in high-mass star-forming regions. Hot corinos, like their high mass counterparts, are sources of a rich inventory of complex organic molecules. The proposed EVLA spectral line survey will provide much needed spatial information of molecular species and complement surveys in the millimeter and submillimeter bands (80, 150, 250 and 350 GHz) that have been just completed with the IRAM and JCMT telescopes. A survey of the 450 GHz band is in process now with APEX and IRAS16293-2422 is a primary target of Herschel, which will observe this source between 500 and 2000 GHz with the Herschel HIFI spectrometer. The EVLA survey will extend the spectral line passbands and effectively inventory the molecules found toward IRAS16293-2422, in addition to adding crucial information on large prebiotic molecules. This is an unique opportunity because in the end, astronomers will have an almost complete inventory of the molecular composition and complexity in a Sun-like protostar and knowing the chemical composition around this object is of paramount importance not only by itself, but above all because it will allow us to look back to the chemistry of our own pre-solar nebula.