The VIMOS VLT Deep Survey: The faint type-1 AGN sample

I. Gavignaud; A. Bongiorno; S. Paltani; G. Mathez; G. Zamorani; P. Møller; J. P. Picat; V. Le Brun; B. Marano; O. Le Fèvre; D. Bottini; B. Garilli; D. Maccagni; R. Scaramella; M. Scodeggio; L. Tresse; G. Vettolani; A. Zanichelli; C. Adami; M. Arnaboldi; S. Arnouts; S. Bardelli; M. Bolzonella; A. Cappi; S. Charlot; P. Ciliegi; T. Contini; S. Foucaud; P. Franzetti; L. Guzzo; O. Ilbert; A. Iovino; H. J. McCracken; C. Marinoni; A. Mazure; B. Meneux; R. Merighi; R. Pellò; A. Polio; L. Pozzetti; M. Radovich; E. Zucca; M. Bondi; G. Busarello; O. Cucciati; S. De La Torre; L. Gregorini; F. Lamareille; Y. Mellier; P. Merluzzi; V. Ripepi; D. Rizzo; D. Vergani

doi:10.1051/0004-6361:20065376

The VIMOS VLT Deep Survey: The faint type-1 AGN sample

I. Gavignaud, A. Bongiorno, S. Paltani, G. Mathez, G. Zamorani, P. Møller, J. P. Picat, V. Le Brun, B. Marano, O. Le Fèvre, D. Bottini, B. Garilli, D. Maccagni, R. Scaramella, M. Scodeggio, L. Tresse, G. Vettolani, A. Zanichelli, C. Adami, M. ArnaboldiS. Arnouts, S. Bardelli, M. Bolzonella, A. Cappi, S. Charlot, P. Ciliegi, T. Contini, S. Foucaud, P. Franzetti, L. Guzzo, O. Ilbert, A. Iovino, H. J. McCracken, C. Marinoni, A. Mazure, B. Meneux, R. Merighi, R. Pellò, A. Polio, L. Pozzetti, M. Radovich, E. Zucca, M. Bondi, G. Busarello, O. Cucciati, S. De La Torre, L. Gregorini, F. Lamareille, Y. Mellier, P. Merluzzi, V. Ripepi, D. Rizzo, D. Vergani

Exact Sciences School

Research output: Contribution to journal › Article › peer-review

39 Citations (Scopus)

Abstract

We present the type-1 active galactic nuclei (AGN) sample extracted from the VIMOS VLT Deep Survey's first observations of 21000 spectra in 1.75 deg ². This sample, which is purely magnitude-limited and free of morphological or color-selection biases, contains 130 broad-line AGN (BLAGN) spectra with redshift up to 5. Our data are divided into a wide (I _AB ≤ 22.5) and a deep (I _AB ≤ 24) subsample containing 56 and 74 objects, respectively. Because of its depth and selection criteria, this sample is uniquely suited for studying the population of faint type-1 AGN. Our measured surface density (∼472 ± 48 BLAGN per square degree with I _AB ≤ 24) is significantly higher than that of any other optically selected sample of BLAGN with spectroscopic confirmation. By applying a morphological and color analysis to our AGN sample, we find that (1) ∼23% of the AGN brighter than I _AB = 22.5 are classified as extended, and this percentage increases to ∼42% for those with z < 1.6; (2) a non-negligible fraction of our BLAGN are lying close to the color-space area occupied by stars in the u* - g′ versus g′ - r′ color-color diagram. This leads us to the conclusion that the classical optical-ultraviolet preselection technique, if employed at such deep magnitudes (I _AB = 22.5) in conjuction with a preselection of point-like sources, can miss up to ∼35% of the AGN population. Finally, we present a composite spectrum of our sample of objects. While the continuum shape is very similar to that of the SDSS composite at short wavelengths, it is much redder than that of the SDSS composite at λ ≥ 3000 Å. We interpret this as due to significant contamination from emission of the host galaxies, as expected from the faint absolute magnitudes sampled by our survey.

Original language	English
Pages (from-to)	79-90
Number of pages	12
Journal	Astronomy and Astrophysics
Volume	457
Issue number	1
DOIs	https://doi.org/10.1051/0004-6361:20065376
Publication status	Published - Oct 2006

Keywords

Catalogs
Galaxies: Seyfert
Galaxies: active
Quasars: general
Surveys

ASJC Scopus subject areas

Astronomy and Astrophysics
Space and Planetary Science

Access to Document

10.1051/0004-6361:20065376

Cite this

Gavignaud, I., Bongiorno, A., Paltani, S., Mathez, G., Zamorani, G., Møller, P., Picat, J. P., Le Brun, V., Marano, B., Le Fèvre, O., Bottini, D., Garilli, B., Maccagni, D., Scaramella, R., Scodeggio, M., Tresse, L., Vettolani, G., Zanichelli, A., Adami, C., ... Vergani, D. (2006). The VIMOS VLT Deep Survey: The faint type-1 AGN sample. Astronomy and Astrophysics, 457(1), 79-90. https://doi.org/10.1051/0004-6361:20065376

@article{6515062fdd434324af1a453c15f0521d,

title = "The VIMOS VLT Deep Survey: The faint type-1 AGN sample",

abstract = "We present the type-1 active galactic nuclei (AGN) sample extracted from the VIMOS VLT Deep Survey's first observations of 21000 spectra in 1.75 deg 2. This sample, which is purely magnitude-limited and free of morphological or color-selection biases, contains 130 broad-line AGN (BLAGN) spectra with redshift up to 5. Our data are divided into a wide (I AB ≤ 22.5) and a deep (I AB ≤ 24) subsample containing 56 and 74 objects, respectively. Because of its depth and selection criteria, this sample is uniquely suited for studying the population of faint type-1 AGN. Our measured surface density (∼472 ± 48 BLAGN per square degree with I AB ≤ 24) is significantly higher than that of any other optically selected sample of BLAGN with spectroscopic confirmation. By applying a morphological and color analysis to our AGN sample, we find that (1) ∼23% of the AGN brighter than I AB = 22.5 are classified as extended, and this percentage increases to ∼42% for those with z < 1.6; (2) a non-negligible fraction of our BLAGN are lying close to the color-space area occupied by stars in the u* - g′ versus g′ - r′ color-color diagram. This leads us to the conclusion that the classical optical-ultraviolet preselection technique, if employed at such deep magnitudes (I AB = 22.5) in conjuction with a preselection of point-like sources, can miss up to ∼35% of the AGN population. Finally, we present a composite spectrum of our sample of objects. While the continuum shape is very similar to that of the SDSS composite at short wavelengths, it is much redder than that of the SDSS composite at λ ≥ 3000 {\AA}. We interpret this as due to significant contamination from emission of the host galaxies, as expected from the faint absolute magnitudes sampled by our survey.",

keywords = "Catalogs, Galaxies: Seyfert, Galaxies: active, Quasars: general, Surveys",

author = "I. Gavignaud and A. Bongiorno and S. Paltani and G. Mathez and G. Zamorani and P. M{\o}ller and Picat, {J. P.} and {Le Brun}, V. and B. Marano and {Le F{\`e}vre}, O. and D. Bottini and B. Garilli and D. Maccagni and R. Scaramella and M. Scodeggio and L. Tresse and G. Vettolani and A. Zanichelli and C. Adami and M. Arnaboldi and S. Arnouts and S. Bardelli and M. Bolzonella and A. Cappi and S. Charlot and P. Ciliegi and T. Contini and S. Foucaud and P. Franzetti and L. Guzzo and O. Ilbert and A. Iovino and McCracken, {H. J.} and C. Marinoni and A. Mazure and B. Meneux and R. Merighi and R. Pell{\`o} and A. Polio and L. Pozzetti and M. Radovich and E. Zucca and M. Bondi and G. Busarello and O. Cucciati and {De La Torre}, S. and L. Gregorini and F. Lamareille and Y. Mellier and P. Merluzzi and V. Ripepi and D. Rizzo and D. Vergani",

year = "2006",

month = oct,

doi = "10.1051/0004-6361:20065376",

language = "English",

volume = "457",

pages = "79--90",

journal = "Astronomy and Astrophysics",

issn = "0004-6361",

publisher = "EDP Sciences",

number = "1",

}

Gavignaud, I, Bongiorno, A, Paltani, S, Mathez, G, Zamorani, G, Møller, P, Picat, JP, Le Brun, V, Marano, B, Le Fèvre, O, Bottini, D, Garilli, B, Maccagni, D, Scaramella, R, Scodeggio, M, Tresse, L, Vettolani, G, Zanichelli, A, Adami, C, Arnaboldi, M, Arnouts, S, Bardelli, S, Bolzonella, M, Cappi, A, Charlot, S, Ciliegi, P, Contini, T, Foucaud, S, Franzetti, P, Guzzo, L, Ilbert, O, Iovino, A, McCracken, HJ, Marinoni, C, Mazure, A, Meneux, B, Merighi, R, Pellò, R, Polio, A, Pozzetti, L, Radovich, M, Zucca, E, Bondi, M, Busarello, G, Cucciati, O, De La Torre, S, Gregorini, L, Lamareille, F, Mellier, Y, Merluzzi, P, Ripepi, V, Rizzo, D & Vergani, D 2006, 'The VIMOS VLT Deep Survey: The faint type-1 AGN sample', Astronomy and Astrophysics, vol. 457, no. 1, pp. 79-90. https://doi.org/10.1051/0004-6361:20065376

TY - JOUR

T1 - The VIMOS VLT Deep Survey

T2 - The faint type-1 AGN sample

AU - Gavignaud, I.

AU - Bongiorno, A.

AU - Paltani, S.

AU - Mathez, G.

AU - Zamorani, G.

AU - Møller, P.

AU - Picat, J. P.

AU - Le Brun, V.

AU - Marano, B.

AU - Le Fèvre, O.

AU - Bottini, D.

AU - Garilli, B.

AU - Maccagni, D.

AU - Scaramella, R.

AU - Scodeggio, M.

AU - Tresse, L.

AU - Vettolani, G.

AU - Zanichelli, A.

AU - Adami, C.

AU - Arnaboldi, M.

AU - Arnouts, S.

AU - Bardelli, S.

AU - Bolzonella, M.

AU - Cappi, A.

AU - Charlot, S.

AU - Ciliegi, P.

AU - Contini, T.

AU - Foucaud, S.

AU - Franzetti, P.

AU - Guzzo, L.

AU - Ilbert, O.

AU - Iovino, A.

AU - McCracken, H. J.

AU - Marinoni, C.

AU - Mazure, A.

AU - Meneux, B.

AU - Merighi, R.

AU - Pellò, R.

AU - Polio, A.

AU - Pozzetti, L.

AU - Radovich, M.

AU - Zucca, E.

AU - Bondi, M.

AU - Busarello, G.

AU - Cucciati, O.

AU - De La Torre, S.

AU - Gregorini, L.

AU - Lamareille, F.

AU - Mellier, Y.

AU - Merluzzi, P.

AU - Ripepi, V.

AU - Rizzo, D.

AU - Vergani, D.

PY - 2006/10

Y1 - 2006/10

N2 - We present the type-1 active galactic nuclei (AGN) sample extracted from the VIMOS VLT Deep Survey's first observations of 21000 spectra in 1.75 deg 2. This sample, which is purely magnitude-limited and free of morphological or color-selection biases, contains 130 broad-line AGN (BLAGN) spectra with redshift up to 5. Our data are divided into a wide (I AB ≤ 22.5) and a deep (I AB ≤ 24) subsample containing 56 and 74 objects, respectively. Because of its depth and selection criteria, this sample is uniquely suited for studying the population of faint type-1 AGN. Our measured surface density (∼472 ± 48 BLAGN per square degree with I AB ≤ 24) is significantly higher than that of any other optically selected sample of BLAGN with spectroscopic confirmation. By applying a morphological and color analysis to our AGN sample, we find that (1) ∼23% of the AGN brighter than I AB = 22.5 are classified as extended, and this percentage increases to ∼42% for those with z < 1.6; (2) a non-negligible fraction of our BLAGN are lying close to the color-space area occupied by stars in the u* - g′ versus g′ - r′ color-color diagram. This leads us to the conclusion that the classical optical-ultraviolet preselection technique, if employed at such deep magnitudes (I AB = 22.5) in conjuction with a preselection of point-like sources, can miss up to ∼35% of the AGN population. Finally, we present a composite spectrum of our sample of objects. While the continuum shape is very similar to that of the SDSS composite at short wavelengths, it is much redder than that of the SDSS composite at λ ≥ 3000 Å. We interpret this as due to significant contamination from emission of the host galaxies, as expected from the faint absolute magnitudes sampled by our survey.

AB - We present the type-1 active galactic nuclei (AGN) sample extracted from the VIMOS VLT Deep Survey's first observations of 21000 spectra in 1.75 deg 2. This sample, which is purely magnitude-limited and free of morphological or color-selection biases, contains 130 broad-line AGN (BLAGN) spectra with redshift up to 5. Our data are divided into a wide (I AB ≤ 22.5) and a deep (I AB ≤ 24) subsample containing 56 and 74 objects, respectively. Because of its depth and selection criteria, this sample is uniquely suited for studying the population of faint type-1 AGN. Our measured surface density (∼472 ± 48 BLAGN per square degree with I AB ≤ 24) is significantly higher than that of any other optically selected sample of BLAGN with spectroscopic confirmation. By applying a morphological and color analysis to our AGN sample, we find that (1) ∼23% of the AGN brighter than I AB = 22.5 are classified as extended, and this percentage increases to ∼42% for those with z < 1.6; (2) a non-negligible fraction of our BLAGN are lying close to the color-space area occupied by stars in the u* - g′ versus g′ - r′ color-color diagram. This leads us to the conclusion that the classical optical-ultraviolet preselection technique, if employed at such deep magnitudes (I AB = 22.5) in conjuction with a preselection of point-like sources, can miss up to ∼35% of the AGN population. Finally, we present a composite spectrum of our sample of objects. While the continuum shape is very similar to that of the SDSS composite at short wavelengths, it is much redder than that of the SDSS composite at λ ≥ 3000 Å. We interpret this as due to significant contamination from emission of the host galaxies, as expected from the faint absolute magnitudes sampled by our survey.

KW - Catalogs

KW - Galaxies: Seyfert

KW - Galaxies: active

KW - Quasars: general

KW - Surveys

UR - http://www.scopus.com/inward/record.url?scp=33749044184&partnerID=8YFLogxK

U2 - 10.1051/0004-6361:20065376

DO - 10.1051/0004-6361:20065376

M3 - Article

AN - SCOPUS:33749044184

SN - 0004-6361

VL - 457

SP - 79

EP - 90

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

IS - 1

ER -

The VIMOS VLT Deep Survey: The faint type-1 AGN sample

Abstract

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this