89 research outputs found
SDSS J163459.82+204936.0: A Ringed Infrared-Luminous Quasar with Outflows in both Absorption and Emission Lines
SDSS J1634+2049 is a local (z = 0.1293) infrared-luminous quasar with LIR=
10^11.91 Lsun. We present a detailed multiwavelength study of both the host
galaxy and the nucleus. The host galaxy demonstrates violent, obscured star
formation activities with SFR ~ 140 Msun yr^-1, estimated from either the PAH
emission or IR luminosity. The optical to NIR spectra exhibit a blueshifted
narrow cuspy component in Hb, HeI5876,10830 and other emission lines
consistently with an offset velocity of ~900 km/s, as well as additional
blueshifting phenomena in high-ionization lines , while there exist blueshifted
broad absorption lines (BALs) in NaID and HeI*3889,10830, indicative of the AGN
outflows producing BALs and emission lines. Constrained mutually by the several
BALs with CLOUDY, the physical properties of the absorption-line outflow are
derived as follows: 10^4 < n_H <= 10^5 cm^-3, 10^-1.3 <= U <= 10^-0.7 and
10^22.5<= N_H <= 10^22.9 cm^-2 , similar to those derived for the emission-line
outflows. The similarity suggests a common origin. Taking advantages of both
the absorption lines and outflowing emission lines, we find that the outflow
gas is located at a distance of 48 - 65 pc from the nucleus, and that the
kinetic luminosity of the outflow is 10^44-10^46 erg s^-1. J1634+2049 has a
off-centered galactic ring on the scale of ~ 30 kpc that is proved to be formed
by a recent head-on collision by a nearby galaxy. Thus this quasar is a
valuable object in the transitional phase emerging out of dust enshrouding as
depicted by the co-evolution scenario.Comment: 13 figures, 6 tables; accepted for publication in Ap
Discovery of An Active Intermediate-Mass Black Hole Candidate in the Barred Bulgeless Galaxy NGC 3319
We report the discovery of an active intermediate-mass black hole (IMBH)
candidate in the center of nearby barred bulgeless galaxy . The
point X-ray source revealed by archival Chandra and XMM-Newton observations is
spatially coincident with the optical and UV galactic nuclei from Hubble Space
Telescope observations. The spectral energy distribution derived from the
unresolved X-ray and UV-optical flux is comparable with active galactic nuclei
(AGNs) rather than ultra-luminous X-ray sources, although its bolometric
luminosity is only . Assuming an Eddington
ratio range between 0.001 and 1, the black hole mass (M_\rm{BH}) will be
located at , placing it in the so-called
IMBH regime and could be the one of the lowest reported so far. Estimates from
other approaches (e.g., fundamental plane, X-ray variability) also suggest
M_\rm{BH}\lesssim10^5~M_{\odot}.Similar to other BHs in bulgeless galaxies,
the discovered IMBH resides in a nuclear star cluster with mass of
. The detection of such a low-mass BH offers us an
ideal chance to study the formation and early growth of SMBH seeds, which may
result from the bar-driven inflow in late-type galaxies with a prominent bar
such as .Comment: ApJ accepted, 2 tables, 6 figure
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