J/A+A/584/A106 Catalogues of variable AGNs (Simm+, 2015)
Pan-STARRS1 variability of XMM-COSMOS AGN. I. Impact on photometric redshifts.
Simm T., Saglia R., Salvato M., Bender R., Burgett W.S., Chambers K.C.,
Draper P.W., Flewelling H., Kaiser N., Kudritzki R.-P., Magnier E.A.,
Metcalfe N., Tonry J.L., Wainscoat R.J., Waters C.
<Astron. Astrophys. 584, A106 (2015)>
=2015A&A...584A.106S 2015A&A...584A.106S (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; Photometry
Keywords: catalogs - methods: data analysis - techniques: photometric -
galaxies: active - galaxies: distances and redshifts -
X-rays: galaxies
Abstract:
Upcoming large area sky surveys like Euclid and eROSITA, which are
dedicated to studying the role of dark energy in the expansion history
of the Universe and the three-dimensional mass distribution of matter,
crucially depend on accurate photometric redshifts. The identification
of variable sources, such as active galactic nuclei (AGNs), and the
achievable redshift accuracy for varying objects are important in view
of the science goals of the Euclid and eROSITA missions.
We probe AGN optical variability for a large sample of X-ray-selected
AGNs in the XMM-COSMOS field, using the multi-epoch light curves
provided by the Pan-STARRS1 (PS1) 3n and Medium Deep Field surveys.
To quantify variability we employed a simple statistic to estimate the
probability of variability and the normalized excess variance to
measure the variability amplitude. Utilizing these two variability
parameters, we defined a sample of varying AGNs for every PS1 band. We
investigated the influence of variability on the calculation of
photometric redshifts by applying three different input photometry
sets for our fitting procedure. For each of the five PS1 bands gP1,
rP1, iP1, zP1, and yP1, we chose either the epochs minimizing
the interval in observing time, the median magnitude values, or
randomly drawn light curve points to compute the redshift. In
addition, we derived photometric redshifts using PS1 photometry
extended by GALEX/IRAC bands.
Description:
Catalogues of X-ray-selected, point-like and isolated AGNs with more
than two detections in the Pan-STARRS1 (PS1) 3pi and MDF04 surveys.
The tables list basic information such as the identifier number,
coordinates, number of light curve points, and light curve median, as
well as the variability parameters used to define samples of variable
AGNs. This information is provided for both the 3pi and MDF04 samples
in the five PS1 bands gP1, rP1, iP1, zP1, and yP1, see
section 4.2 and Appendix C of the paper.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
agn3pi_g.dat 131 151 Variability parameters of 3pi sample (gP1 band)
agn3pi_r.dat 131 116 Variability parameters of 3pi sample (rP1 band)
agn3pi_i.dat 131 50 Variability parameters of 3pi sample (iP1 band)
agn3pi_z.dat 131 95 Variability parameters of 3pi sample (zP1 band)
agn3pi_y.dat 131 36 Variability parameters of 3pi sample (yP1 band)
agnmdf_g.dat 131 187 Variability parameters of MDF04 sample (gP1 band)
agnmdf_r.dat 131 184 Variability parameters of MDF04 sample (rP1 band)
agnmdf_i.dat 131 165 Variability parameters of MDF04 sample (iP1 band)
agnmdf_z.dat 131 135 Variability parameters of MDF04 sample (zP1 band)
agnmdf_y.dat 131 76 Variability parameters of MDF04 sample (yP1 band)
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See also:
J/A+A/497/635 : XMM-Newton wide-field survey in COSMOS field (Cappelluti+ 2009)
J/ApJ/750/99 : The Pan-STARRS1 photometric system (Tonry+, 2012)
Byte-by-byte Description of file (# headlines): agn*
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Bytes Format Units Label Explanations
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3- 7 I5 --- XID XMM-COSMOS identifier number (1)
9- 17 F9.5 deg RAdeg Right ascension (J2000)
19- 26 F8.6 deg DEdeg Declination (J2000)
28- 29 I2 --- N Number of light curve points
34- 51 E18.14 --- V ?=999 V parameter (Eq. 6) (2)
53- 69 E17.14 --- rms Excess variance (Eq. 7)
71- 86 E16.12 --- e_rms Error on excess variance (Eq. 8)
88-100 F13.10 mag magmed Median magnitude of light curve
102-117 F16.14 mag e_magmed Median error of light curve points
120-131 F12.10 mag Dmag Max(mag)-Min(mag) of light curve
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Note (1): From Cappelluti et al. (2009A&A...497..635C 2009A&A...497..635C, Cat. J/A+A/497/635)
Note (2): V=999.0 corresponds to V=Infinity.
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Acknowledgements:
Torben Simm, tsimm(at)mpe.mpg.de
(End) Torben Simm [MPE], Patricia Vannier [CDS] 08-Oct-2015