The Nançay H i Zone of Avoidance survey of 2MASS bright galaxies
Résumé
To complement the Two Micron All Sky Survey (2MASS) Redshift Survey (2MRS) and the 2MASS Tully-Fisher survey (2MTF), a search for 21 cm HI line emission of 2MASS bright galaxy candidates has been pursued along the dust-obscured plane of the Milky Way with the 100 m Nancay Radio Telescope. For our sample selection, we adopted an isophotal extinction-corrected K-s-band magnitude limit of K-s(o) = 11.(m)25, corresponding to the first 2MRS data release and 2MTF, for which the 2MASX completeness level remains fairly constant deep into the Zone of Avoidance (ZoA). About one thousand galaxies without prior redshift measurement accessible from Nancay (Dec. > -40 degrees) were observed to an rms noise level of similar to 3 mJy for the velocity range -250 to 10 600 km s(-1). This resulted in 220 clear and 12 marginal detections of the target sample. Only few detections have redshifts above 8000 km s(-1) due to recurring radio frequency interference. A further 29 detections and 6 marginals have their origin in non-target galaxies in the telescope beam. The newly detected galaxies are on average considerably more HI-rich (mostly 10(9)-10(10) M-circle dot) compared to systematic (blind) HI surveys. The HI detections reveal various new filaments crossing the mostly uncharted northern ZoA (e.g. at l similar to 90 degrees, 130 degrees, and 160 degrees), whilst consolidating galaxy agglomerations in Monoceros and Puppis (l similar to 220 degrees and 240 degrees). Considerably new insight has been gained about the extent of the Perseus-Pisces Supercluster through the confirmation of a ridge (l similar to 160 degrees) encompassing the 3C 129 cluster that links Perseus-Pisces to Lynx, and the continuation of the second Perseus-Pisces arm (l similar to 90 degrees) across the ZoA.
Origine : Fichiers éditeurs autorisés sur une archive ouverte
Loading...