The Northern HIPASS catalogue - data presentation, completeness and reliability measures

Wong, O. I.; Ryan-Weber, E. V.; Garcia‐Appadoo, D. A.; Webster, R. L.; Staveley‐Smith, L.; Zwaan, M. A.; Meyer, M.; Barnes, David G.; Kilborn, V. A.; Bhathal, Ragbir; Blok, W. J. G. de; Disney, M. J.; Doyle, M. T.; Drinkwater, Michael J.; Ekers, R. D.; Freeman, K. C.; Gibson, Brad K.; Gurovich, S.; Harnett, J.; Henning, P. A.; Jerjen, Helmut; Kesteven, Michael; Knezek, Patricia; Koribalski, B. S.; Mader, Stacy; Marquarding, M.; Minchin, R. F.; O’Brien, J. C.; Putman, Mary E.; Ryder, S. D.; Sadler, E. M.; Stevens, J.; Stewart, I. M.; Stootman, F.; Waugh, M.

doi:10.1111/j.1365-2966.2006.10846.x

Cited by 172 publications

(175 citation statements)

References 17 publications

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“…We choose these sets of objects as examples of astrophysical scenarios worthy of examination. We have reported additional explorations (such as the correlation with galaxies in the HI Parkes All Sky Survey [34,35]) in [36].…”

Section: Examination Of the Arrival Directions In Relation To Other Cmentioning

confidence: 99%

Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter

Abreu

Aglietta

Ahn

et al. 2010

Astroparticle Physics

290

210

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a b s t r a c tData collected by the Pierre Auger Observatory through 31 August 2007 showed evidence for anisotropy in the arrival directions of cosmic rays above the Greisen-Zatsepin-Kuz'min energy threshold, 6 Â 10 19 eV. The anisotropy was measured by the fraction of arrival directions that are less than 3.1°from the position of an active galactic nucleus within 75 Mpc (using the Véron-Cetty and Véron 12th catalog). An updated measurement of this fraction is reported here using the arrival directions of cosmic rays recorded above the same energy threshold through 31 December 2009. The number of arrival directions has increased from 27 to 69, allowing a more precise measurement. The correlating fraction is 38 þ7 À6 %, compared with 21% expected for isotropic cosmic rays. This is down from the early estimate of 69 þ11 À13 %.1 Deceased.

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Section: Examination Of the Arrival Directions In Relation To Other Cmentioning

confidence: 99%

Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter

Abreu

Aglietta

Ahn

et al. 2010

Astroparticle Physics

290

210

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“…The HIPASS (Barnes et al 2001) includes the complete Southern sky and the Northern sky up to +25.5 degrees in Declination. The Northern part of the survey is described in Wong et al (2006). This survey currently has the best available H i brightness sensitivity yet published.…”

Section: Introductionmentioning

confidence: 99%

Diffuse neutral hydrogen in the H i Parkes All Sky Survey

Popping

Braun

2011

A&A

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Context. Observations of neutral hydrogen can provide a wealth of information about the distribution and kinematics of galaxies.To learn more about large scale structures and accretion processes, the extended environment of galaxies must also be observed. Numerical simulations predict a cosmic web of extended structures and gaseous filaments. Aims. To detect H i beyond the ionisation edge of galaxy disks, column density sensitivities have to be achieved that probe the regime of Lyman limit systems. Typically H i observations are limited to a brightness sensitivity of N HI ∼ 10 19 cm −2 but this has to be improved by at least an order of magnitude. Methods. In this paper, reprocessed data is presented that was originally observed for the H i Parkes All Sky Survey (HIPASS). HIPASS provides complete coverage of the region that has been observed for the Westerbork Virgo Filament H i Survey (WVFS), presented in accompanying papers, and thus is an excellent product for data comparison. The region of interest extends from 8 to 17 hours in right ascension and from −1 to 10 degrees in declination. Although the original HIPASS product already has good flux sensitivity, the sensitivity and noise characteristics can be significantly improved with a different processing method. Results. The newly processed data has an 1σ rms flux sensitivity of ∼10 mJy beam −1 over 26 km s −1 , corresponding to a column density sensitivity of ∼3 × 10 17 cm −2 . While the rms sensitivity is improved by only a modest 20%, the more substantial benefit is in the reduction of spectral artefacts near bright sources by more than an order of magnitude. In the reprocessed region we confirm all previously catalogued HIPASS sources and have identified 29 additional sources of which 14 are completely new H i detections. We derived spectra and moment maps for all detections together with total fluxes determined both by integrating the spectrum and by integrating the flux in the moment maps within the source radius. Extended emission or companions were sought in the nearby environment of each discrete detection. Ten extra-galactic filaments are marginally detected within the moment maps. Conclusions. With the improved sensitivity after reprocessing and its large sky coverage, the HIPASS data is a valuable resource for detection of faint H i emission. This faint emission can correspond to extended halos, dwarf galaxies, tidal remnant and potentially diffuse filaments that represent the trace neutral fraction of the Cosmic Web.

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“…The survey spans 11 degrees in Declination from −1 to +10 degrees and 135 degrees in Right Ascension between 8 and 17 h. This survey has a point source sensitivity of 16 mJy beam −1 over 16 km s −1 corresponding to a column density of N HI ∼ 3.5 × 10 16 cm −2 . A&A 528, A28 (2011) The second data product presented in Popping & Braun (2011b) is reprocessed data, using original data that has been observed for the H i Parkes All Sky Survey (Barnes et al 2001;Wong et al 2006). The 1500 square degree region overlapping the WVFS was reprocessed to permit comparison between these data products and detections.…”

Section: Introductionmentioning

confidence: 99%

The WSRT Virgo Hi filament survey

Popping

Braun²

2011

A&A

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Context. 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 inter-galactic medium, where numerical simulations predict a cosmic web of extended structures and gaseous filaments. Aims. To observe the extended environment of galaxies, column density sensitivities have to be achieved that probe the regime of Lyman limit systems. H i observations are typically limited to a brightness sensitivity of N HI ∼ 10 19 cm −2 , but this must be improved upon by ∼2 orders of magnitude. Methods. In this paper we present the interferometric data of the Westerbork Virgo H i 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 300 × 25 m 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 H i detections of diffuse systems with moderate angular resolution. Results. The survey maps 135 degrees in Right Ascension between 8 and 17 h 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 N HI ∼ 10 18 cm −2 . An unbiased search has been done with a high significance threshold as well a search with a lower significance limit but requiring an optical counterpart. In total, 199 objects have been detected, of which 17 are new H i detections. Conclusions. By observing at extreme hour angles with the WSRT, a filled aperture can be simulated in projection, with a very good brightness sensitivity, comparable to that of a single dish telescope. Despite some technical challenges, the data provide valuable constraints on faint, circum-galactic H i features.

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The Northern HIPASS catalogue - data presentation, completeness and reliability measures

Cited by 172 publications

References 17 publications

Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter

Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter

Diffuse neutral hydrogen in the H i Parkes All Sky Survey

The WSRT Virgo Hi filament survey

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