2016A&A...596A..64S


C.D.S. - SIMBAD4 rel 1.7 - 2020.06.01CEST04:51:45

2016A&A...596A..64S - Astronomy and Astrophysics, volume 596A, 64-64 (2016/12-1)

Do some AGN lack X-ray emission?

SIMMONDS C., BAUER F.E., THUAN T.X., IZOTOV Y.I., STERN D. and HARRISON F.A.

Abstract (from CDS):

Context. 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.
Aims. Here we study in detail several candidate active galactic nuclei (AGN) found in metal-poor hosts.
Methods. 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.
Results. Despite having clear broad optical emission lines that are long-lived (≳10-13yr), these candidate AGN appear to lack associated strong X-ray and hard UV emission, lying at least 1-2 dex off the known AGN correlations. If they are IMBHs/SMBHs, our constraints imply that they either are not actively accreting, their accretion disks are fully obscured along our line-of-sight, or their accretion disks are not producing characteristic high energy emission. Alternatively, if they are not AGN, then their luminous broad emission lines imply production by extreme stellar processes. The latter would have profound implications on the applicability of broad lines for mass estimates of massive black holes.

Abstract Copyright: © ESO, 2016

Journal keyword(s): galaxies: active - galaxies: Seyfert - X-rays: galaxies - galaxies: dwarf

VizieR on-line data: <Available at CDS (J/A+A/596/A64): table1.dat fits/*>

Status at CDS:  

CDS comments: Paragraph.1 RGG 188 and HLX-1 not identified.

Simbad objects: 20

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Number of rows : 20

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 SHOC 29 Q? 00 45 29.1456110403 +13 39 08.731770243   22.07 21.03     ~ 5 0
2 SN 1978K SN* 03 17 38.620 -66 33 03.40   13.0       SNII 187 1
3 BD+52 913 WD* 05 05 30.6182785658 +52 49 51.920797126 10.25 11.44 11.69 11.93 12.108 DA.8 979 0
4 SN 2006jd SN* 08 02 07.43 +00 48 31.5   22.5 21.8 20.4 21.3 SNIIn 75 1
5 LEDA 24384 Sy1 08 40 29.9132803308 +47 07 10.244168570   18.2       ~ 59 0
6 SN 2005ip SN* 09 32 06.42 +08 26 44.4 18.1 18.7 18.5     SNII 126 1
7 Mrk 709 H2G 09 49 18.065 +16 52 44.83   17.0       ~ 35 0
8 2MASS J10253030+1402078 Sy1 10 25 30.2915316274 +14 02 07.394686616   20.59 19.77     ~ 6 0
9 Feige 34 HS* 10 39 36.7377085527 +43 06 09.209752646 9.613 10.91 11.14 11.319 11.464 sdOp 602 0
10 SDSS J104755.92+073951.2 Sy1 10 47 55.9261965913 +07 39 51.229156062   20.04 19.81     ~ 8 1
11 Mrk 177 AGN 11 33 23.474 +55 04 20.61   16.0       ~ 31 0
12 SDSS J113323.97+550415.9 Sy1 11 33 23.978 +55 04 15.90           ~ 13 1
13 NAME G 1200-2038 Sy1 12 02 56.8 -20 56 03           ~ 134 0
14 SDSS J122245.72+360218.4 AGN 12 22 45.7 +36 02 19   21.55 20.60     ~ 3 0
15 NGC 4395 Sy2 12 25 48.8639154223 +33 32 48.694684028 10.84 10.54 10.11 9.98   ~ 982 1
16 HZ 44 HS* 13 23 35.2632775627 +36 07 59.545982652 10.186 11.42 11.65 12.00 11.995 sdBN0VIIHe28 369 0
17 M 101 GiP 14 03 12.583 +54 20 55.50   8.46 7.86 7.76   ~ 2534 2
18 NGC 5471 EmG 14 04 28.627 +54 23 52.84           ~ 229 1
19 LEDA 1944409 Sy1 15 36 56.439 +31 22 48.12   17.67 17.52     ~ 13 0
20 Feige 110 HS* 23 19 58.3995050606 -05 09 56.170282845 10.360 11.45 11.50 11.970 12.145 sdO8VIIIHe5 548 1

    Equat.    Gal    SGal    Ecl

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2020.06.01-04:51:45

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