J/MNRAS/465/302 Lyman continuum leaking AGN in SSA22 field (Micheva+, 2017)
Lyman continuum leaking AGN in the SSA22 field.
Micheva G., Iwata I., Inoue A.K.
<Mon. Not. R. Astron. Soc., 465, 302-315 (2017)>
=2017MNRAS.465..302M 2017MNRAS.465..302M (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; Redshifts ; Photometry, infrared ;
Photometry, UBVRI ; Photometry, SDSS
Keywords: galaxies: evolution - galaxies: high-redshift - intergalactic medium -
cosmology: observations - diffuse radiation
Abstract:
Subaru/SuprimeCam narrow-band photometry of the SSA22 field reveals
the presence of four Lyman continuum (LyC) candidates among a sample
of 14 active galactic nuclei (AGNs). Two show offsets and likely have
stellar LyCin nature or are foreground contaminants. The remaining two
LyC candidates are type I AGN. We argue that the average LyC escape
fraction of high-redshift, low-luminosity AGN is not likely to be
unity, as often assumed in the literature. From direct measurement we
obtain the average LyC-to-UV flux density ratio and ionizing
emissivity for a number of AGN classes and find it at least a factor
of 2 lower than values obtained assuming fesc=1. Comparing to recent
Lyα forest measurements, AGNs at redshift z∼3 make up at most
∼12 per cent and as little as ∼5 per cent of the total
ionizing budget. Our results suggest that AGNs are unlikely to
dominate the ionization budget of the Universe at high redshifts.
Description:
We assembled a catalogue of AGN from the SSA22 field by first
searching among our base sample of 308 galaxies with z>3.06 from
Micheva et al. (2015, Cat. J/MNRAS/365/316, hereafter Paper I). With
this redshift cutoff, the NB359 filter samples LyC radiation.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
agn.dat 231 14 AGN catalog
--------------------------------------------------------------------------------
See also:
J/MNRAS/465/316 : Lyman continuum LAEs and LBGs in SSA22 field (Micheva+, 2017)
Byte-by-byte Description of file: agn.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- Seq [1/14] Running number (number)
4- 8 A5 --- Name ID of AGN in paper (AGN1/AGN14) (id)
10 I1 --- Type [1/2] Spectral AGN type: Type 1 or Type 2
(agn_type)
12- 22 F11.7 deg RAdeg Right ascension (J2000) (ra_r)
24- 32 F9.7 deg DEdeg Declination (J2000) (dc_r)
34- 38 F5.3 --- z Spectroscopic redshift (redshift)
40- 43 F4.2 arcsec FWHM R band FWHM in arcsec (r_modelFWHM)
45- 50 F6.3 mag N3mag ?=- Growth curve total AB mag in NB359
(n3_modelmag)
52- 56 F5.3 mag e_N3mag ?=- Growth curve total AB mag error in NB359
(n3_modelmagerr)
58- 63 F6.3 mag Bmag ?=- Growth curve total AB mag in B
(b_modelmag)
65- 69 F5.3 mag e_Bmag ?=- Growth curve total AB mag error in B
(b_modelmagerr)
71- 76 F6.3 mag N4mag Growth curve total AB mag in NB497
(n4_modelmag)
78- 82 F5.3 mag e_N4mag Growth curve total AB mag error in NB497
(n4_modelmagerr)
84- 89 F6.3 mag Vmag Growth curve total AB mag in V (v_modelmag)
91- 95 F5.3 mag e_Vmag Growth curve total AB mag error in V
(v_modelmagerr)
97-102 F6.3 mag Rmag Growth curve total AB mag in R (r_modelmag)
104-108 F5.3 mag e_Rmag Growth curve total AB mag error in R
(r_modelmagerr)
110-115 F6.3 mag i'mag Growth curve total AB mag in i' (i_modelmag)
117-121 F5.3 mag e_i'mag Growth curve total AB mag error in i'
(i_modelmagerr)
123-128 F6.3 mag z'mag Growth curve total AB mag in z' (z_modelmag)
130-134 F5.3 mag e_z'mag Growth curve total AB mag error in z'
(z_modelmagerr)
136-141 F6.3 mag N3magapR ?=- Diameter=1.2 arcsec aperture AB mag in
NB359 at R band position (n3ap12r_mag)
143-147 F5.3 mag e_N3magapR ?=- Diameter=1.2 arcsec aperture AB mag error
in NB359 at R band position (n3ap12r_magerr)
149-154 F6.3 mag BmagapR ?=- Diameter=1.2 arcsec aperture AB mag in
B at R band position (bap12r_mag)
156-160 F5.3 mag e_BmagapR ?=- Diameter=1.2 arcsec aperture AB mag error
in B at R band position (bap12r_magerr)
162-167 F6.3 mag N4magapR Diameter=1.2 arcsec aperture AB mag in
NB497 at R band position (n4ap12r_mag)
169-173 F5.3 mag e_N4magapR Diameter=1.2 arcsec aperture AB mag error in
NB497 at R band position (n4ap12r_magerr)
175-180 F6.3 mag VmagapR Diameter=1.2 arcsec aperture AB mag in V at
R band position (vap12r_mag)
182-186 F5.3 mag e_VmagapR Diameter=1.2 arcsec aperture AB mag error in
V at R band position (vap12r_magerr)
188-193 F6.3 mag RmagapR Diameter=1.2 arcsec aperture AB mag in R at
R band position (rap12r_mag)
195-199 F5.3 mag e_RmagapR Diameter=1.2 arcsec aperture AB mag error in
R at R band position (rap12r_magerr)
201-206 F6.3 mag i'magapR Diameter=1.2 arcsec aperture AB mag in i' at
R band position (iap12r_mag)
208-212 F5.3 mag e_i'magapR Diameter=1.2 arcsec aperture AB mag error in
i' at R band position (iap12r_magerr)
214-219 F6.3 mag z'magapR Diameter=1.2 arcsec aperture AB mag in z' at
R band position (zap12r_mag)
221-225 F5.3 mag e_z'magapR Diameter=1.2 arcsec aperture AB mag error in
z' at R band position (zap12r_magerr)
227-231 F5.3 mag AV Galactic Extinction using IRSA (Av_SandF) (1)
--------------------------------------------------------------------------------
Note (1): Schlafly and Finkbeiner, 2011ApJ...737..103S 2011ApJ...737..103S.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
References:
Micheva et al., Paper I, 2017MNRAS.465..316M 2017MNRAS.465..316M, Cat. J/MNRAS/465/316
(End) Patricia Vannier [CDS] 08-Jun-2018