J/A+A/617/A118 APM 08279+5255 optical-to-UV spectrum (Saturni+, 2018)
The rest-frame UV-to-optical spectroscopy of APM 08279+5255.
BAL classification and black hole mass estimates.
Saturni F.G., Bischetti M., Piconcelli E., Bongiorno A., Cicone C.,
Feruglio C., Fiore F., Gallerani S., Giustini M., Piranomonte S.,
Vietri G., Vignali C.
<Astron. Astrophys. 617, A118 (2018)>
=2018A&A...617A.118S 2018A&A...617A.118S (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; QSOs ; Spectroscopy
Keywords: galaxies: active - quasars: general - quasars: absorption lines -
quasars: emission lines - quasars: supermassive black holes -
quasars: individual: APM 08279+5255
Abstract:
We present the analysis of the rest-frame optical-to-UV spectrum of
APM 08279+5255, a well-known lensed broad absorption line (BAL) quasar
at z=3.911. The spectroscopic data are taken with the optical DOLoRes
and near-IR NICS instruments at TNG, and include the previously
unexplored range between CIII] λ1910 and [OIII]
λλ4959,5007. We investigate the possible presence
of multiple BALs by computing "balnicity" and absorption indexes
(i.e. BI, BI0 and AI) for the transitions SiIV λ1400, CIV
λ1549, AlIII λ1860 and MgII λ2800. No clear
evidence for the presence of absorption features is found in addition
to the already known, prominent BAL associated to C IV, which supports
a high-ionization BAL classification for APM 08279+5255. We also study
the properties of the [OIII], Hβ and MgII emission lines. We
find that [OIII] is intrinsically weak (F[OIII]/FHβ≲0.04),
as it is typically found in luminous quasars with a strongly
blueshifted CIV emission line (2500km/s for APM 08279+5255). We
compute the single-epoch black hole mass based on MgII and Hβ
broad emission lines, finding MBH=(2/3)*1010µ-1M☉,
with the magnification factor µ that can vary between 4 and 100
according to CO and rest-frame UV-to-mid-IR imaging respectively.
Using a MgII equivalent width (EW)-to-Eddington ratio relation, the
EWMgII∼27Å measured for APM 08279+5255 translates into an
Eddington ratio of ∼0.4, which is more consistent with µ=4.
This magnification factor also provides a value of MBH that is
consistent with recent reverberation-mapping measurements derived from
CIV and SiIV.
Description:
APM 08279+5255 calibrated spectrum before dereddening (green dashed
line in Fig. 1) with corresponding 1σ uncertainties.
Assume a redshift of 3.911 to correct for time dilation. See Sect. 2
for details on the dereddening procedure.
Objects:
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RA (2000) DE Designation(s)
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08 31 41.71 +52 45 17.6 APM 08279+5255 = QSO J0831+5245
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
apm08279.dat 44 8088 APM 08279+5255 calibrated spectrum before
dereddening with corresponding 1σ
uncertainties
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See also:
J/A+A/608/A30 : APM 08279+5255 CO(4-3) spectrum (Feruglio+, 2017)
Byte-by-byte Description of file: apm08279.dat
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Bytes Format Units Label Explanations
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1- 12 F12.6 0.1nm Lambda Observer-frame wavelength
19- 28 E10.4 10mW/m2/nm Flux Observer-frame specific flux
(erg/cm2/s/Å)
35- 44 E10.4 10mW/m2/nm e_Flux Observer-frame flux uncertainty
(erg/cm2/s/Å)
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Acknowledgements:
Francesco G. Saturni, francesco.saturni(at)inaf.it
(End) Patricia Vannier [CDS] 28-Aug-2018