J/A+A/617/A38 The hydrogen gas outflow in 3C236 (Schulz+, 2018)
Mapping the neutral atomic hydrogen gas outflow in the restarted radio
galaxy 3C 236.
Schulz R., Morganti R., Nyland K., Paragi Z., Mahony E.K., Oosterloo T.
<Astron. Astrophys. 617, A38 (2018)>
=2018A&A...617A..38S 2018A&A...617A..38S (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei; Galaxies, radio ; VLBI ; Interstellar medium
Keywords: galaxies: active - galaxies: jets - galaxies: individual: 3C 236 -
galaxies: ISM - techniques: high angular resolution -
ISM: jets and outflows
Abstract:
The energetic feedback that is generated by radio jets in active
galactic nuclei (AGNs) has been suggested to be able to produce fast
outflows of atomic hydrogen (HI) gas which can be studied in
absorption at high spatial resolution. We have used the Very Large
Array (VLA) and a global very-long-baseline-interferometry (VLBI)
array to locate and study in detail the HI outflow discovered with the
Westerbork Synthesis Radio Telescope (WSRT) in the restarted radio
galaxy 3C 236. Based on the VLA data, the presence of a blue-shifted
wing of the HI with a width of ∼1000km/s. This HI outflow is
partially recovered by the VLBI observation. In particular, we detect
four clouds with masses of 0.28-1.5x104M☉ with VLBI that do
not follow the regular rotation of most of the HI. Three of these
clouds are located, in projection, against the nuclear region on
scales of ≲40pc, while the fourth is cospatial to the southeast lobe
at a projected distance of ∼270pc. Their velocities are between 150
and 640km/s blueshifted with respect to the velocity of the
disk-related HI. These findings suggest that the outflow is at least
partly formed by clouds, as predicted by some numerical simulations,
and that it originates already in the inner (few tens of pc) region of
the radio galaxy. Our results indicate that the entire outflow might
consist of many clouds, possibly with comparable properties as those
clearly detected, but also distributed at larger radii from the
nucleus where the lower brightness of the lobe does not allow us to
detect them. However, we cannot rule out a diffuse component of the
outflow. Because 3C 236 is a low excitation radio galaxy, it is less
likely that the optical AGN is able to produce strong radiative winds.
This leaves the radio jet as the main driver for the HI outflow.
Description:
CLEAN-image and cube as FITS-files used for Fig. 1, 3, 4, and 5 and to
extract the VLBI spectra in Fig. 2.
Objects:
--------------------------------------------------
RA (2000) DE Designation(s)
--------------------------------------------------
10 06 01.75 +34 54 10.4 3C236 = OHIO L 305
--------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
list.dat 120 2 List of fits files
fits/* . 2 Individual fits files
--------------------------------------------------------------------------------
See also:
J/A+A/549/A58 : 3C 236 CO maps (Labiano+, 2013)
Byte-by-byte Description of file: list.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 23 I4 --- Nx Number of pixels along X-axis
25- 28 I4 --- Ny Number of pixels along Y-axis
30- 32 I3 --- Nz ? Number of slices for the data cube
34- 43 A10 --- Obs.Date Observation date (YYYY-MM-DD)
45- 55 E11.6 Hz Freq Observed frequency or lower value of
frequency interval
57- 67 E11.6 Hz Freq2 ? Upper value of frequency interval
69- 75 F7.1 Hz dFreq ? Frequency resolution for the data cube
77- 82 I6 Kibyte size Size of FITS file
84- 98 A15 --- FileName Name of FITS file, in subdirectory fits
100-120 A21 --- Title Title of the FITS file
--------------------------------------------------------------------------------
Acknowledgements:
Robert Schulz, schulz(at)astron.nl
(End) Patricia Vannier [CDS] 26-Jun-2018