The WSRT Virgo Hi filament survey II; Cross Correlation Data

Abstract

The extended environment of galaxies contains a wealth of information about the formation and life cycle of galaxies which are regulated by accretion and feedback processes. Observations of neutral hydrogen are routinely used to image the high brightness disks of galaxies and to study their kinematics. Deeper observations will give more insight into the distribution of diffuse gas in the extended halo of the galaxies and the IGM, where numerical simulations predict a cosmic web of extended structures and gaseous filaments. To observe the extended environment of galaxies, column density sensitivities have to be achieved that probe the regime of Lyman limit systems. HI observations are typically limited to a brightness sensitivity of NHI~10^19 cm-2, but this must be improved upon by ~2 orders of magnitude. In this paper we present the interferometric data of the Westerbork Virgo HI Filament Survey (WVFS) - the total power product of this survey has been published in an earlier paper. By observing at extreme hour angles, a filled aperture is simulated of 300x25 meters in size, that has the typical collecting power and sensitivity of a single dish telescope, but the well defined bandpass characteristics of an interferometer. With the very good surface brightness sensitivity of the data, we hope to make new HI detections of diffuse systems with moderate angular resolution. The survey maps 135 degrees in Right Ascension between 8 and 17 hours and 11 degrees in Declination between -1 and 10 degrees, including the galaxy filament connecting the Local Group with the Virgo Cluster. Only positive declinations could be completely processed and analysed due to projection effects. A typical flux sensitivity of 6 mJy beam-1 over 16 km s-1 is achieved, that corresponds to a brightness sensitivity of NHI~10^18 cm-2. In total, 199 objects have been detected, of which 17 are new HI detections. (Abridged)

19 pages plus appendix, 19 figures, appendix will only appear in online format. Accepted for publication in A&A

References in corpus (4)

• A High-Resolution Survey of Low-Redshift QSO Absorption Lines: Statistics and Physical Conditions of O VI Absorbers
• The Northern HIPASS catalogue - Data presentation, completeness and reliability measures
• Physical Properties, Baryon Content, and Evolution of the LyαForest: New Insights from High Resolution Observations at z < 0.4
• The WSRT Virgo HI filament survey I; Total Power Data

Cited by in corpus (11)

• Duchamp: a 3D source finder for spectral-line data
• Herschel-ATLAS: The Surprising Diversity of Dust-Selected Galaxies in the Local Submillimetre Universe
• Virgo Filaments I: Processing of gas in cosmological filaments around the Virgo cluster
• An Empirical Determination of the Dust Mass Absorption Coefficient, ${\kappa }_d$, Using the Herschel Reference Survey
• The Dark Matter Distributions in Low-Mass Disk Galaxies. II. The Inner Density Profiles
• The HI content of extremely metal-deficient blue compact dwarf galaxies
• Herschel Spectroscopy of Early Type Galaxies
• Study of galaxies in the Lynx-Cancer void. VI. HI-observations with the Nancay Radio Telescope
• CHANG-ES XXXII: Spatially Resolved Thermal/Nonthermal Separation from Radio Data Alone -- New Probes into NGC 3044 and NGC 5775
• Diffuse neutral hydrogen in the HI Parkes All Sky Survey
• Pearls on a string: Dark and bright galaxies on a strikingly straight and narrow filament