J/A+A/485/475 AMIGA. VI. Radio fluxes of the isolated galaxies (Leon+ 2008)
The AMIGA sample of isolated galaxies.
VI. Radio continuum properties of isolated galaxies: a very radio quiet sample.
Leon S., Verdes-Montenegro L., Sabater J., Espada D., Lisenfeld U.,
Ballu A., Verley S., Bergond G., Garcia E.
<Astron. Astrophys. 485, 475 (2008)>
=2008A&A...485..475L 2008A&A...485..475L
ADC_Keywords: Surveys ; Galaxies, radio
Keywords: galaxies: evolution - galaxies: luminosity function -
radio continuum: galaxies - surveys - mass function
Abstract:
This paper is part of a series that describes the results of the AMIGA
(Analysis of the interstellar Medium of Isolated GAlaxies) project,
studying the largest sample of very isolated galaxies in the local
Universe. The study of the radio properties of the AMIGA sample is
intended to characterize the radio continuum emission for a sample
least affected by the local environment, thus providing a reference
against which less isolated and interacting samples can be compared.
Radio continuum data at 325, 1420, and 4850MHz were extracted from
the WENSS, NVSS/FIRST, and GB6 surveys, respectively. The source
extractions have been obtained from reprocessing the data and new
detections added to the cross- matched detections with the respective
survey catalogs. We focus on the complete AMIGA subsample composed of
719 galaxies.
A catalog of radio fluxes was obtained from the above four surveys.
Comparison between the NVSS and FIRST detections indicates that the
radio continuum is coming from disk-dominated emission in spiral
galaxies, in contrast to the results found in high-density
environments where nuclear activity is more frequent. The comparison
of the radio continuum power with a comparable sample, which is
however not selected with respect to its environment, the Condon et
al. UGC-SF sample of star-forming field galaxies, shows a lower mean
value for the AMIGA sample. We have obtained radio-to-optical flux
ratios (R) using the NVSS radio continuum flux. The distribution of R
for the AMIGA galaxies is consistent with a sample dominated by radio
emission from star formation (SF) and a small number of active
galactic nuclei (AGN), with less than 3% of the sample with R>100. We
derived the radio luminosity function (RLF) and total power density of
the radio continuum emission for the AMIGA sample at 1.4GHz, and
compared them with results from other low-redshift studies. The
Schechter fit of the RLF indicates a major weight of the
low-luminosity galaxies. The results indicate the very low level of
radio continuum emission in our sample of isolated galaxies, which is
dominated by mild disk SF. It confirms thus the AMIGA sample as a
suitable template to effectively quantify the role of interactions in
samples extracted from denser environments.
Description:
Table 2 gives the radio flux density and radio power at 325/352MHz
(from the WENSS survey), 1420MHz (from the NVSS survey) and 4850MHz
(from GB6 survey) for the whole original Catalog of Isolated Galaxies
(CIG, Karachentseva, 1973, VII/82), including 1050 galaxies. Note
that object #781 is a globular cluster (Pal 15) and should not be
considered. The codes for the origin of data are as follows: 0 stands
for no data, 1 if included in the original catalog (WENSS VIII/62,
NVSS VIII/65, or GB6 VIII/40), 2 if determined from this work and
3 if extracted from NED. Reference code 4 indicates FIRST (VIII/71)
detection without a corresponding NVSS detection.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 76 1050 Radio-continuum parameters of 1050 CIG galaxies
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See also:
VII/82 : Catalogue of Isolated Galaxies (Karachentseva+ 1986)
VIII/40 : GB6 catalog of radio sources (Gregory+ 1996)
VIII/62 : The Westerbork Northern Sky Survey (Leiden, 1998)
VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)
VIII/71 : The FIRST Survey Catalog, Version 03Apr11 (Becker+ 2003)
J/A+A/436/443 : AMIGA I. Recession velocities (Verdes-Montenegro+, 2005)
J/A+A/449/937 : AMIGA II. Morphological refinement (Sulentic+, 2006)
J/A+A/462/507 : AMIGA III. IRAS data (Lisenfeld+, 2007)
J/A+A/470/505 : AMIGA IV. Neighbours around CIG galaxies (Verley+, 2007)
J/A+A/472/121 : AMIGA V. Isolation parameters (Verley+, 2007)
J/A+A/486/73 : AMIGA VII. FIR and radio study (Sabater+, 2008)
J/A+A/532/A117 : AMIGA VIII. Flux ratio asymmetry parameter (Espada+, 2011)
http://www.iaa.es/AMIGA.html : AMIGA HomePage
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- CIG CIG number (Cat. VII/82) K73 NNNN in Simbad
6 A1 --- l_F325 [<] upper limit on 352MHz flux (1)
7- 12 F6.2 mJy F325 ?=0.00 Flux at 325 or 352MHz (1)
14- 18 F5.2 mJy e_F325 ?=0.00 Error on the flux at 325/352MHz
20 A1 --- l_P325 [<] upper limit on 352MHz power (1)
21- 26 F6.3 [W/Hz] P325 ?=0.000 Radio power at 325/352MHz
28 I1 --- r_F325 [0/2] Code for data at 325MHz (2)
30 A1 --- l_F1420 [<] upper limit on 1420MHz flux (1)
31- 36 F6.2 mJy F1420 ?=0.00 Flux at 1420MHz
38- 42 F5.2 mJy e_F1420 ?=0.00 Error on the flux at 1420MHz
44 A1 --- l_P1420 [<] upper limit on 352MHz power (1)
45- 50 F6.3 [W/Hz] P1420 ?=0.000 Radio power at 1420MHz
52 I1 --- r_F1420 [1/3] Code for data at 1420MHz (2)
54 A1 --- l_F4850 [<] upper limit on 4850MHz flux (1)
55- 60 F6.2 mJy F4850 ?=0.00 Flux at 4850MHz
62- 66 F5.2 mJy e_F4850 ?=0.00 Error on the flux at 4850MHz
68 A1 --- l_P4850 [<] upper limit on 4850MHz power (1)
69- 74 F6.3 [W/Hz] P4850 ?=0.000 Radio power at 4850MHz
76 I1 --- r_F4850 [0/2] Code for data at 4850MHz (2)
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Note (1): The original table used negative values for upper limits.
Note (2): Codes for the origin of the data are as follows:
0 = no data
1 = original catalog values (WENSS (325MHz, Cat. VIII/62),
NVSS (1420MHz, Cat. VIII/65) or GB6 (4850MHz, Cat. VIII/40)
2 = this work
3 = from NED
4 = FIRST detection without NVSS counterpart
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Acknowledgements: Jose Sabater Montes, jsm(at)iaa.es
Stephane Leon, leon(at)iram.es
History:
* 21-Apr-2008: Original version
* 07-Aug-2008: Replaced negative values by the '<' limit sign.
References:
Leon et al., Paper I 2003A&A...411..391L 2003A&A...411..391L, Cat. J/A+A/411/391
Sulentic et al., Paper II 2006A&A...449..937S 2006A&A...449..937S Cat. J/A+A/449/937
Lisenfeld et al., Paper III 2007A&A...462..507L 2007A&A...462..507L, Cat. J/A+A/462/507
Verley et al., Paper IV 2007A&A...470..505V 2007A&A...470..505V, Cat. J/A+A/470/505
Verley et al., Paper V 2007A&A...472..121V 2007A&A...472..121V, Cat. J/A+A/472/121
Sabater et al., Paper VII 2008A&A...486...73S 2008A&A...486...73S, Cat. J/A+A/486/73
Espada et al., Paper VIII 2011A&A...532A.117E 2011A&A...532A.117E, Cat. J/A+A/532/A117
Lisenfeld et al., Paper IX 2011A&A...534A.102L 2011A&A...534A.102L, Cat. J/A+A/534/A102
Fernandez Lorenzo et al., Paper X 2012A&A...540A..47F 2012A&A...540A..47F, Cat. J/A+A/540/A47
(End) Stephane Leon [IRAM, Spain], Patricia Vannier [CDS] 21-Apr-2008