J/A+A/596/A64 4 AGN optical spectra (Simmonds+, 2016)
Do some AGN lack X-ray emission?
Simmonds C., Bauer F.E., Thuan T.X., Izotov Y.I., Stern D., Harrison F.A.
<Astron. Astrophys. 596, A64 (2016)>
=2016A&A...596A..64S 2016A&A...596A..64S (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; Spectroscopy
Keywords: galaxies: active - galaxies: Seyfert - X-rays: galaxies -
galaxies: dwarf
Abstract:
Intermediate-Mass Black Holes (IMBHs) are thought to be the seeds of
early Supermassive Black Holes (SMBHs). While ≳100 IMBH and small
SMBH candidates have been identified in recent years, few have been
robustly confirmed to date, leaving their number density in
considerable doubt. Placing firmer constraints both on the methods
used to identify and confirm IMBHs/SMBHs, as well as characterizing
the range of host environments that IMBHs/SMBHs likely inhabit is
therefore of considerable interest and importance. Additionally,
finding significant numbers of IMBHs in metal-poor systems would be
particularly intriguing, since such systems may represent local
analogs of primordial galaxies, and therefore could provide clues of
early accretion processes.
Here we study in detail several candidate Active Galactic Nuclei (AGN)
found in metal-poor hosts.
We utilize new X-ray and optical observations to characterize these
metal-poor AGN candidates and compare them against known AGN
luminosity relations and well-characterized IMBH/SMBH samples.
Description:
We targeted with dedicated Chandra observations the four most extreme
ELGs reported by Izotov and Thuan (2008ApJ...687..133I 2008ApJ...687..133I) (J1025+1402,
J1047+0739, J0045+1339, and J1222+3602). For completeness, we also
report the results of archival Chandra observations for three weaker
objects (J1536+3122, J0840+4707, and J1404+5423) in the parent Izotov
et al. (2007ApJ...671.1297I 2007ApJ...671.1297I) sample which also have broad Hα
emission lines.
New optical spectra for galaxies J0045+1339, J1025+1402, J1047+0739,
and J1222+3602 were obtained using the Apache Point Observatory (APO)
3.5m telescope using the Dual Imaging Spectrograph (DIS) in both the
blue and red wavelength ranges. The sources were observed on several
occasions between 2007-2015.
New optical spectra for galaxies J0045+1339 and J1222+3602 were
obtained using the MODS instrument on the Large Binocular Telescope
(LBT) on UT 2013 October 27 and UT 2015 May 18, respectively.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 131 4 List of AGN with spectra
fits/* . 6 Individual fits files
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- SDSS SDSS name 9JHHMMSS.ss+DDMMSS.s)
21- 30 A10 --- Name SDSS short name (JHHMM+DDMM)
32- 33 I2 h RAh Right ascension (J2000)
35- 36 I2 min RAm Right ascension (J2000)
38- 41 F4.1 s RAs Right ascension (J2000)
43 A1 --- DE- Declination sign (J2000)
44- 45 I2 deg DEd Declination (J2000)
47- 48 I2 arcmin DEm Declination (J2000)
50- 51 I2 arcsec DEs Declination (J2000)
53- 59 F7.5 --- z Redshift
61- 64 A4 --- Inst Instrument
66- 75 A10 "date" Obs.date Observation date
77-103 A27 --- FileName1 Name of the fits file with spectra in
subdirectory fits
105-131 A27 --- FileName2 Name of the fits file with spectra in
subdirectory fits
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Acknowledgements:
Charlotte Simmonds, cpsimmonds(at)uc.cl
(End) Patricia Vannier [CDS] 09-Nov-2016