J/A+A/626/A9 Obscured AGN at 1.5<z<3.0 (Mignoli+, 2019)
Obscured AGN at 1.5<z<3.0 from the zCOSMOS-deep Survey.
I. Properties of the emitting gas in the narrow-line region.
Mignoli M., Feltre A., Bongiorno A., Calura F., Gilli R., Vignali C.,
Zamorani G., Lilly S.J., Le Fevre O., Bardelli S., Bolzonella M.,
Bordoloi R., Le Brun V., Caputi K.I., Cimatti A., Diener C., Garilli B.,
Koekemoer A.M., Maier C., Mainieri V., Peng Y., Perez Montero E.,
Silverman J.D., Zucca E.
<Astron. Astrophys. 626, A9 (2019)>
=2019A&A...626A...9M 2019A&A...626A...9M (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; QSOs ; Spectra, optical
Keywords: galaxies: active - galaxies: fundamental parameters -
galaxies: evolution - quasars: emission lines - X-rays: galaxies -
line: formation
Abstract:
We select a sample of 90 obscured (type 2) AGN with 1.45<z<3.05 from
the zCOSMOS-deep galaxy sample by 5 sigma-detection of the
high-ionization CIV λ1549 narrow emission line. The presence of
this feature in a galaxy spectrum is often associated with nuclear
activity, and the selection effectiveness has been also confirmed by
ultraviolet (UV) emission line ratio diagnostic diagrams. Applying the
same selection technique, a sample of 102 unobscured (type 1) AGN was
collected. Taking advantage of the large amount of multi-band data
available in the COSMOS field, we investigate the properties of the
CIV-selected type 2 AGN, focusing on their host galaxies, X-ray
emission and UV emission lines. Finally, we investigate the physical
properties of the ionized gas in the Narrow Line Region (NLR) of this
type 2 AGN sample, combining the analysis of strong UV emission lines
with predictions from photo-ionization models. We find that, in order
to successfully reproduce the relative intensity of UV emission lines
of the selected high-z type 2 AGN, two new ingredients in the
photo-ionization models are fundamental,i.e. small inner radii of the
NLR (∼90pc for LAGN=1045erg/s) and the internal dissipative
micro-turbulence of the gas emitting clouds (with vmicr∼100km/s).
With these modified models, we compute the gas-phase metallicity of
the NLR, and our measurements indicate a statistically significant
evolution of the metal content with redshift. Finally, we do not
observe, in our CIV-selected type 2 AGN sample, a strong relationship
between the NLR gas metallicity and the stellar mass of the host
galaxy.
Description:
We present the sample of 90 CIV-selected AGN in the redshift range
1.45<z<3.05, extracted from the zCOSMOS-deep survey, classified as
type 2 AGN on the basis of the FWHM of the emission lines.
Spectra of the targeted objects have been obtained using the R200
LR-Blue grism, which provides a spectral coverage from 3700 to 6800Å.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
sample.dat 84 90 Sample of unobscured type 2 AGN
fits/* . 266 Individual fits files
(spectra and probability density functions)
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Byte-by-byte Description of file: sample.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- zCOSMOS Id from the zCOSMOS-deep survey
8- 13 F6.4 --- z ? Redshift
15- 29 A15 --- VIMOSsp Name of the fits file with VIMOS spectrum,
in subdirectory fits
31- 36 F6.3 [Msun] logM* ? Stellar mass of the host galaxy
38- 40 F3.1 mag E(B-V) ? AGN extinction provided by the
SED fitting routine
42- 46 F5.2 --- Chi2 ? Chi square goodness of fit
48- 64 A17 --- [O/H]PDF Name of the file with [O/H] probability
density function, in subdirectory fits
66- 84 A19 --- UPDF Name of the file with logU probability
density function, in subdirectory fits
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Acknowledgements:
Marco Mignoli, marco.mignoli(at)inaf.it
(End) Patricia Vannier [CDS] 12-Apr-2019