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J/other/RMxAA/47.361   AGN activity in isolated SDSS galaxies   (Coziol+, 2011)

The nature and origin of Narrow-line AGN Activity in a sample of isolated SDSS galaxies. Coziol R., Torres-Papaqui J.P., Plauchu-Frayn I., Islas-Islas J.M., Ortega-Minakata R.A., Neri-Larios D.M., Andernach H. <Rev. Mex. Astron. Astrofis. 47, 361 (2011)> =2011RMxAA..47..361C
ADC_Keywords: Galaxies, spectra ; Active gal. nuclei ; Abundances ; Equivalent widths Keywords: Galaxies:spectra ; AGN ; Equivalent_widths Abstract: We discuss the nature and origin of the nuclear activity observed in a sample of 292 SDSS narrow-emission-line galaxies, considered to have formed and evolved in isolation. All these galaxies are spiral like and show some kind of nuclear activity. The fraction of Narrow Line AGNs (NLAGNs) and Transition type Objects (TOs; a NLAGN with circumnuclear star formation) is relatively high, amounting to 64% of the galaxies. There is a definite trend for the NLAGNs to appear in early-type spirals, while the star forming galaxies and TOs are found in later-type spirals. We verify that the probability for a galaxy to show an AGN characteristic increases with the bulge mass of the galaxy (Torres-Papaqui et al. 2011), and find evidence that this trend is really a by-product of the morphology, suggesting that the AGN phenomenon is intimately connected with the formation process of the galaxies. Consistent with this interpretation, we establish a strong connection between the astration rate -- the efficiency with which the gas is transformed into stars - the AGN phenomenon, and the gravitational binding energy of the galaxies: the higher the binding energy, the higher the astration rate and the higher the probability to find an AGN. The NLAGNs in our sample are consistent with scaled-down or powered-down versions of quasars and Broad Line AGNs. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file nelg1.dat 134 292 Basic and spectroscopic properties of isolated Narrow-emission line galaxies (NELG) (tables 1 and 2) nelg2.dat 59 292 Masses, gas metallicities and absolute B magnitudes for the isolated NELGs (tables 4, 6, 8 and 9)
Byte-by-byte Description of file: nelg1.dat
Bytes Format Units Label Explanations
1- 4 A4 --- --- [SDSS] 6- 24 A19 --- SDSS SDSS object name according to SDSS-DR7 26- 34 F9.5 deg RAdeg Right Ascension (J2000) 36- 44 F9.5 deg DEdeg Declination (J2000) 46- 51 F6.4 --- z redshift according to SDSS-DR7 53- 55 A3 --- morph morphological classification by authors 57- 60 F4.1 kpc rP90 Petrosian radius at 90% from SDSS-DR7 62- 65 F4.2 --- conc concentration index from SDSS-DR7 (1) 67- 71 F5.2 [Lsun] logL.K log of K20-band luminosity from 2MASS 73- 77 F5.2 [yr] logt* log of the mean stellar age of the stellar populations consistent with STARLIGHT 79- 84 F6.3 [---] lgO3Hb log(O[III]/Hβ) emission-line ratio 86- 91 F6.3 [---] lgN2Ha log(N[II]/Hα) emission-line ratio 93- 95 A3 --- Act Activity Type (2) 97-100 F4.2 [Lsun] lgLHa log(Hα) emission-line luminosity 102-104 I3 km/s sigV ? stellar velocity dispersion 106-110 F5.2 [10-7W] lgL5100 log of 5100-Å continuum luminosity (erg/s) 112-134 A23 --- NEDnam preferred name in NASA/IPAC Extragalactic Database (NED;
Note (1): ratio of the two Petrosian radii (CI = R(90%)/R(50%)) Note (2): Activity types are: AGN = active galactic nucleus; SFG = star forming galaxy; TO = transition object between the former two
Byte-by-byte Description of file: nelg2.dat
Bytes Format Units Label Explanations
1- 4 A4 --- --- [SDSS] 6- 24 A19 --- SDSS SDSS object name according to SDSS-DR7 26- 30 F5.2 [Msun] lgMblg ? log10 of bulge mass in solar masses 32- 36 F5.2 [Msun] lgMBH ? log10 of black hole mass in solar masses 38- 42 F5.2 [Msun] lgMB log10 of B-band based mass in solar masses (3) 44- 46 A3 --- Act Activity Type (repeated from table1and2) 48- 52 F5.2 [Sun] logOH gas metallicity log(O/H) relative to solar (4) 54- 59 F6.2 mag BMAG absolute magnitude in the B band (5)
Note (3): see Sect. 3.2 of article for details Note (4): see Sect. 3.4 of article for details Note (5): obtained using the Johnson-B band magnitude synthesized from the SDSS magnitudes (1996AJ....111.1748F). The uncertainty is of the order of 0.05 mag.
Acknowledgements: Heinz Andernach, heinz(at)
(End) Heinz Andernach [Universidad de Guanajuato, Mexico] 23-Sep-2011
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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