J/A+A/564/A128 Continuum and CO maps of 3C 293 (Labiano+, 2014)
Fueling the central engine of radio galaxies.
III. Molecular gas and star formation efficiency of 3C 293.
Labiano A., Garcia-Burillo S., Combes F., Usero A., Soria-Ruiz R.,
Piqueras Lopez J., Fuente A., Hunt L., Neri R.
<Astron. Astrophys. 564, A128 (2014)>
=2014A&A...564A.128L 2014A&A...564A.128L
ADC_Keywords: Galaxies, radio ; Redshifts ; Carbon monoxide
Keywords: galaxies: individual: 3C 293 - galaxies: ISM -
galaxies: kinematics and dynamics - galaxies: active -
ISM: jets and outflows - galaxies: star formation
Abstract:
Powerful radio galaxies show evidence of ongoing active galactic
nuclei (AGN) feedback, mainly in the form of fast, massive outflows.
But it is not clear how these outflows affect the star formation of
their hosts.
We investigate the different manifestations of AGN feedback in the
evolved, powerful radio source 3C 293 and their impact on the
molecular gas of its host galaxy, which harbors young star-forming
regions and fast outflows of H i and ionized gas.
We study the distribution and kinematics of the molecular gas of
3C 293 using high spatial resolution observations of the 12CO(1-0)
and 12CO(2-1) lines, and the 3mm and 1 continuum taken with the IRAM
Plateau de Bure interferometer. We mapped the molecular gas of 3C 293
and compared it with the dust and star-formation images of the host.
We searched for signatures of outflow motions in the CO kinematics,
and re-examined the evidence of outflowing gas in the HI spectra. We
also derived the star formation rate (SFR) and star formation
efficiency (SFE) of the host with all available SFR tracers from the
literature, and compared them with the SFE of young and evolved radio
galaxies and normal star-forming galaxies.
The 12CO(1-0) emission line shows that the molecular gas in 3C 293
is distributed along a massive (M(H2)∼2.2x1010M☉)
∼24" (21kpc) diameter warped disk, that rotates around the AGN. Our
data show that the dust and the star formation are clearly associated
with the CO disk. The 12CO(2-1) emission is located in the inner
7kpc (diameter) region around the AGN, coincident with the inner part
of the 12CO(1-0) disk. Both the 12CO(1-0) and 12CO(2-1) spectra
reveal the presence of an absorber against the central regions of 3C
293 that is associated with the disk. We do not detect any fast
(500km/s) outflow motions in the cold molecular gas. The host of 3C
293 shows an SFE consistent with the Kennicutt-Schmidt law of normal
galaxies and young radio galaxies, and it is 10-50 times higher than
the SFE estimated with the 7.7um PAH emission of evolved radio
galaxies. Our results suggest that the apparently low SFE of evolved
radio galaxies may be caused by an underestimation of the SFR and/or
an overestimation of the molecular gas densities in these sources.
The molecular gas of 3C 293, while not incompatible with a mild
AGN-triggered flow, does not reach the high velocities (500km/s)
observed in the HI spectrum. We find no signatures of AGN feedback
in the molecular gas of 3C 293.
Description:
Continuum maps at 1mm and 3mm. Map of the integrated 12CO(2-1)
and 12CO(2-1) lines.
Objects:
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RA (2000) DE Designation(s)
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13 52 17.76 +31 26 46.1 3C 293 = UGC 8782
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 77 4 List of FITS maps
maps/* . 4 Individual FITS maps
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See also:
J/A+A/549/A58 : 3C 236 CO maps (Labiano+, 2013)
Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 25 F6.4 arcsec/pix Scale [0.07/0.141] Scale of the image
27- 29 I3 pix Nx [362] Number of pixels along X-axis
30 A1 --- --- [x]
31- 33 I3 pix Ny [362] Number of pixels along Y-axis
35- 43 A9 --- FileName Name of FITS file in subdirectory maps
45- 77 A33 --- Title Title of the map
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Acknowledgements:
Alvaro Labiano, alvaro.labiano(at)gmail.com
References:
Garcia-Burillo et al., Paper I 2007A&A...468L..71G 2007A&A...468L..71G
Labiano et al., Paper II 2013A&A...549A..58L 2013A&A...549A..58L, Cat. J/A+A/549/A58
(End) Alvaro Labiano [CAB, Spain], Patricia Vannier [CDS] 06-Mar-2014