WATCAT: a tale of wide-angle tailed radio galaxies

¹ Dipartimento di Fisica “Ettore Pancini”, Università di Napoli Federico II, via Cintia, 80126 Napoli, Italy
e-mail: valentina.missaglia@cfa.harvard.edu
² Center for Astrophysics, Harvard & Smithsonian, 60 Garden Street, 02138 Cambridge, MA, USA
³ Dipartimento di Fisica, Università degli Studi di Torino, via Pietro Giuria 1, 10125 Torino, Italy
⁴ Istituto Nazionale di Fisica Nucleare, Sezione di Torino, 10125 Torino, Italy
⁵ INAF – Osservatorio Astrofisico di Torino, via Osservatorio 20, 10025 Pino Torinese, Italy
⁶ Consorzio Interuniversitario per la Fisica Spaziale (CIFS), via Pietro Giuria 1, 10125 Torino, Italy
⁷ INFN, Sezione di Napoli, via Cintia, 80126 Napoli, Italy
⁸ Department of Physics and Astronomy, University of Southampton, Highfield SO17 1BJ, UK
⁹ INAF – Osservatorio Astronomico di Capodimonte, via Moiariello 16, 80131 Napoli, Italy

Received: 14 January 2019
Accepted: 26 February 2019

Abstract

We present a catalog of 47 wide-angle tailed radio galaxies (WATs), the WATCAT, mainly built including a radio morphological classification; WATs were selected by combining observations from the National Radio Astronomy Observatory/Very Large Array Sky Survey (NVSS), the Faint Images of the Radio Sky at Twenty-Centimeters (FIRST), and the Sloan Digital Sky Survey (SDSS). We included in the catalog only radio sources showing two-sided jets with two clear “warmspots” (i.e., jet knots as bright as 20% of the nucleus) lying on the opposite side of the radio core, and having classical extended emission resembling a plume beyond them. The catalog is limited to redshifts z ≤ 0.15, and lists only sources with radio emission extended beyond 30 kpc from the host galaxy. We found that host galaxies of WATCAT sources are all luminous (−20.5 ≳ M_r ≳ −23.7), red early-type galaxies with black hole masses in the range 10⁸ ≲ M_BH ≲ 10⁹ M_⊙. The spectroscopic classification indicates that they are all low-excitation galaxies (LEGs). Comparing WAT multifrequency properties with those of FR I and FR II radio galaxies at the same redshifts, we conclude that WATs show multifrequency properties remarkably similar to FR I radio galaxies, having radio power of typical FR IIs.