The Alfa Zoa Deep Survey: First Results

Abstract

The Arecibo L-band Feed Array Zone of Avoidance (ALFA ZOA) Deep Survey is the deepest and most sensitive blind H I survey undertaken in the ZOA. ALFA ZOA Deep will cover about 300 square degrees of sky behind the Galactic Plane in both the inner ( l b 30 7 5; 2°⩽ ⩽°⩽ |°|) and outer ( l b 175 207 ; 2 1°⩽ ⩽°−°⩽ ⩽ +°) Galaxy, using the Arecibo Radio Telescope. First results from the survey have found 61 galaxies within a 15 square degree area centered on l 192 =°and b = −2°. The survey reached its expected sensitivity of rms = 1 mJy at 9 km s −1 channel resolution, and is shown to be complete above integrated flux, F HI = 0.5 Jy km s −1 . The positional accuracy of the survey is 28″ and detections are found out to a recessional velocity of nearly 19,000 km s −1 . The survey confirms the extent of the Orion and Abell 539 clusters behind the plane of the Milky Way and discovers expansive voids, at 10,000 and 18,000 km s −1 . Twenty-six detections (43%) have a counterpart in the literature, but only two of these have known redshifts. Counterparts are 20% less common beyond v hel = 10,000 km s −1 and 33% less common at extinctions higher than A B = 3.5 mag. The ALFA ZOA Deep survey is able to probe large scale structure beyond redshifts that even the most modern wide-angle surveys have been able to detect in the ZOA at any wavelength.

Void galaxies in the nearby Universe – I. Sample description

“…However, the optical detection of smaller galaxies and dwarfs is affected by both the above substantial extinction and by the crowded stellar environments. Therefore, the major part of galaxies in this region ( 80 per cent) are found via the 21-cm H i radio-line (blind) surveys (HIPASS, ALFALFA) or the dedicated H i surveys to probe the content of ZOA (Staveley-Smith et al 2016;McIntyre 2015). Also, the part of ZOA galaxies were identified via the redshift measurements of extended NIR sources (2MASX) from the Twomicron survey (Skrutskie et al 2006).…”

Searching for Extragalactic Sources in the VISTA Variables in the Vía Láctea Survey

“…In addition, Woudt & KraanKorteweg (2001) studied the neighborhoods of the Crux (  < <  l 289 318 and <  | | b 10 ) and the Great Attractor (  < <  l 289 338 and <  | | b 10 ) regions. Recently, McIntyre et al (2015) presented a blind H I survey named the Arecibo L-band Feed Array Zone of Avoidance (ALFA ZOA) deep Survey, using the Arecibo Radio Telescope. On analyzing an area of 15 square degrees centered on l=192°and b=−2°, they encountered 61 galaxies and concluded that bright galaxies are likely to be identified in infrared surveys, with less probability at higher extinctions.…”

The WSRT ZoA Perseus-Pisces filament wide-field H i imaging survey – I. H i catalogue and atlas

“…With an rms of ∼6 mJy and channel width of 13.2 km s −1 out to ∼12000 km s −1 these surveys together cover the ZoA from = 196 • across the Galactic Bulge to = 52 • . Another recent and more sensitive survey is the Arecibo L-Band Feed Array Zone of Avoidance Survey (ALFA ZoA; Henning et al 2010, McIntyre et al 2015 with an rms of 1 mJy at 9 km s −1 resolution which is mapping the ZoA accessible to the Arecibo telescope (30 • ∼ < ∼ < 75 • and 175 • ∼ < ∼ < 207 • ). All of these surveys have contributed to uncovering gas rich galaxies and structures they belong to in the ZoA.…”