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Sep 18, 2013
09/13
by
Jenny E. Greene
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This article documents our ongoing search for the elusive "intermediate-mass" black holes. These would bridge the gap between the approximately ten solar mass "stellar-mass" black holes that are the end-product of the life of a massive star, and the "supermassive" black holes with masses of millions to billions of solar masses found at the centers of massive galaxies. The discovery of black holes with intermediate mass is the key to understanding whether...
Source: http://arxiv.org/abs/1211.7082v1
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55
Sep 18, 2013
09/13
by
Jenny E. Greene; Luis C. Ho
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eye 55
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We present the first measurement of the black hole (BH) mass function for broad-line active galaxies in the local Universe. Using the ~9000 broad-line active galaxies from the Fourth Data Release of the Sloan Digital Sky Survey, we construct a broad-line luminosity function that agrees very well with the local soft X-ray luminosity function. Using standard virial relations, we then convert observed broad-line luminosities and widths into BH masses. A mass function constructed in this way has...
Source: http://arxiv.org/abs/0705.0020v1
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Sep 19, 2013
09/13
by
Jenny E. Greene; Luis C. Ho
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eye 50
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We discuss the critical importance of black hole mass indicators based on scaling relations in active galaxies. We highlight outstanding uncertainties in these methods and potential paths to substantial progress in the next decade.
Source: http://arxiv.org/abs/0909.5436v1
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Sep 20, 2013
09/13
by
Jenny E. Greene; Luis C. Ho
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eye 46
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We present a pilot study of the X-ray properties of intermediate-mass (~10^5-10^6 M_sun) black holes in active galaxies using the Chandra X-ray telescope. Eight of the 10 active galaxies are detected with a significance of at least 3 sigma, with X-ray luminosities in the range L_(0.5-2 keV) ~ 10^41-10^43 ergs/s. The optical-to-X-ray flux ratios are consistent with expectations, given the known correlations between alpha_ox and ultraviolet luminosity, while a couple of objects appear to be...
Source: http://arxiv.org/abs/astro-ph/0608061v1
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Sep 21, 2013
09/13
by
Jenny E. Greene; Luis C. Ho
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eye 45
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It has been established that virial masses for black holes in low-redshift active galaxies can be estimated from measurements of the optical continuum strength and the width of the broad Hbeta line. Under various circumstances, however, both of these quantities can be challenging to measure or can be subject to large systematic uncertainties. To mitigate these difficulties, we present a new method for estimating black hole masses. From analysis of a new sample of broad-line active galactic...
Source: http://arxiv.org/abs/astro-ph/0508335v1
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6.0
Jun 30, 2018
06/18
by
Julia M. Comerford; Jenny E. Greene
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eye 6
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Offset active galactic nuclei (AGNs) are AGNs that are in ongoing galaxy mergers, which produce kinematic offsets in the AGNs relative to their host galaxies. Offset AGNs are also close relatives of dual AGNs. We conduct a systematic search for offset AGNs in the Sloan Digital Sky Survey, by selecting AGN emission lines that exhibit statistically significant line-of-sight velocity offsets relative to systemic. From a parent sample of 18314 Type 2 AGNs at z
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1405.6711
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Sep 20, 2013
09/13
by
Jenny E. Greene; Luis C. Ho
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We present an initial sample of 19 intermediate-mass black hole candidates in active galactic nuclei culled from the First Data Release of the Sloan Digital Sky Survey. Using the linewidth-luminosity-mass scaling relation established for broad-line active nuclei, we estimate black hole masses in the range of 8 x 10^4 - 10^6 solar masses, a regime in which only two objects are currently known. The absolute magnitudes are faint for active galactic nuclei, ranging from M_g of -15 to -18 mag, while...
Source: http://arxiv.org/abs/astro-ph/0404110v1
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Sep 18, 2013
09/13
by
Jenny E. Greene; Luis C. Ho
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eye 74
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We present an expanded sample of low-mass black holes (BHs) found in galactic nuclei. Using standard virial mass techniques to estimate BH masses, we select from the Fourth Data Release of the Sloan Digital Sky Survey all broad-line active galaxies with masses < 2 x 10^6 M_sun. BHs in this mass regime provide unique tests of the relationship between BHs and galaxies, since their late-type galaxy hosts do not necessarily contain classical bulges. Furthermore, they provide observational...
Source: http://arxiv.org/abs/0707.2617v1
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4.0
Jun 30, 2018
06/18
by
Nadia L. Zakamska; Jenny E. Greene
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We conduct kinematic analysis of the SDSS spectra of 568 obscured luminous quasars, with the emphasis on the kinematic structure of the [OIII]5007 emission line. [OIII] emission tends to show blueshifts and blue excess, which indicates that at least part of the narrow-line gas is undergoing an organized outflow. The velocity width containing 90% of line power ranges from 370 to 4780 km/sec, suggesting outflow velocities up to 2000 km/sec. The velocity width of the [OIII] emission is positively...
Topics: Astrophysics of Galaxies, Astrophysics, Cosmology and Nongalactic Astrophysics
Source: http://arxiv.org/abs/1402.6736
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8.0
Jun 29, 2018
06/18
by
Viraj Pandya; John Mulchaey; Jenny E. Greene
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We present the first comprehensive archival study of the X-ray properties of ultracompact dwarf (UCD) galaxies, with the goal of identifying weakly-accreting central black holes in UCDs. Our study spans 578 UCDs distributed across thirteen different host systems, including clusters, groups, fossil groups, and isolated galaxies. Of the 336 spectroscopically-confirmed UCDs with usable archival Chandra imaging observations, 21 are X-ray-detected. Imposing a completeness limit of...
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1601.01690
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Sep 18, 2013
09/13
by
Ingyin Zaw; Glennys R. Farrar; Jenny E. Greene
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The Pierre Auger Observatory reports that 20 of the 27 highest energy cosmic rays have arrival directions within 3.2 deg of a nearby galaxy in the Veron-Cetty & Veron Catalog of Quasars and Active Galactic Nuclei (12th Ed.), with ~5 of the correlations expected by chance. In this paper we examine the correlated galaxies to gain insight into the possible UHECR sources. We find that 14 of the 21 correlated VCV galaxies are AGNs and we determine their bolometric luminosities. The remaining 7...
Source: http://arxiv.org/abs/0806.3470v1
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3.0
Jun 29, 2018
06/18
by
Semyeong Oh; Jenny E. Greene; Claire N. Lackner
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eye 3
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We investigate two-dimensional image decomposition of nearby, morphologically selected early-type galaxies (ETGs). We are motivated by recent observational evidence of significant size growth of quiescent galaxies and theoretical development advocating a two-phase formation scenario for ETGs. We find that a significant fraction of nearby ETGs show changes in isophotal shape that require multi-component models. The characteristic sizes of the inner and outer component are $\sim 3$ and $\sim 15$...
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1612.06495
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Sep 18, 2013
09/13
by
Luis C. Ho; Jeremy Darling; Jenny E. Greene
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We have conducted a new Arecibo survey for H I emission for 113 galaxies with broad-line (type 1) active galactic nuclei (AGNs) out to recession velocities as high as 35,000 km/s. The primary aim of the study is to obtain sensitive H I spectra for a well-defined, uniformly selected sample of active galaxies that have estimates of their black hole masses in order to investigate correlations between H I properties and the characteristics of the AGNs. H I emission was detected in 66 out of the 101...
Source: http://arxiv.org/abs/0803.2023v1
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Sep 22, 2013
09/13
by
Ruobing Dong; Jenny E. Greene; Luis C. Ho
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eye 62
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We present a systematic X-ray study, the third in a series, of 49 active galactic nuclei with intermediate-mass black holes (IMBH; ~10^5-10^6 M_sun) using Chandra observations. We detect 42 out of 49 targets with a 0.5-2 keV X-ray luminosity 10^41-10^43 erg/s. We perform spectral fitting for the 10 objects with enough counts (>200), and they are all well fit by a simple power-law model modified by Galactic absorption, with no sign of significant intrinsic absorption. While we cannot fit the...
Source: http://arxiv.org/abs/1210.6653v1
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Sep 18, 2013
09/13
by
Luis C. Ho; Jeremy Darling; Jenny E. Greene
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eye 52
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We completed a new survey for H I emission for a large, well-defined sample of 154 nearby (z < 0.1) galaxies with type 1 AGNs. We make use of the extensive database presented in a companion paper to perform a comprehensive appraisal of the cold gas content in active galaxies and to seek new strategies to investigate the global properties of the host galaxies and their relationship to their central black holes (BHs). We show that the BH mass obeys a strong, roughly linear relation with the...
Source: http://arxiv.org/abs/0803.1952v1
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3.0
Jun 30, 2018
06/18
by
Guilin Liu; Nadia L. Zakamska; Jenny E. Greene
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eye 3
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Quasar feedback is suspected to play a key role in the evolution of massive galaxies, by removing or reheating gas in quasar host galaxies and thus limiting the amount of star formation. In this paper we continue our investigation of quasar-driven winds on galaxy-wide scales. We conduct Gemini Integral Field Unit spectroscopy of a sample of luminous unobscured (type 1) quasars, to determine the morphology and kinematics of ionized gas around these objects, predominantly via observations of the...
Topics: Astrophysics of Galaxies, High Energy Astrophysical Phenomena, Astrophysics, Cosmology and...
Source: http://arxiv.org/abs/1401.0536
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48
Sep 23, 2013
09/13
by
Jenny E. Greene; Luis C. Ho; Aaron J. Barth
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eye 48
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We investigate the relationship between black hole mass and host galaxy properties for active galaxies with the lowest black hole masses currently known in galaxy nuclei. Hubble Space Telescope imaging confirms that the host galaxies have correspondingly low luminosity; they are ~1 mag below L*. In terms of morphology, ~60% of the members of the sample are disk-dominated, and all of these are consistent with containing a bulge or (more likely) pseudobulge, while the remainder are compact...
Source: http://arxiv.org/abs/0810.1972v1
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Sep 18, 2013
09/13
by
James S. Ulvestad; Jenny E. Greene; Luis C. Ho
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eye 52
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We have used the Very Large Array (VLA) to search for radio emission from the globular cluster G1 (Mayall-II) in M31. G1 has been reported by Gebhardt et al. to contain an intermediate-mass black hole (IMBH) with a mass of ~2 x 10^4 solar masses. Radio emission was detected within an arcsecond of the cluster center with an 8.4 GHz power of 2 x 10^{15} W/Hz. The radio/X-ray ratio of G1 is a few hundred times higher than that expected for a high-mass X-ray binary in the cluster center, but is...
Source: http://arxiv.org/abs/0704.1458v1
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158
Jul 20, 2013
07/13
by
Yan-Fei Jiang; Jenny E. Greene; Luis C. Ho
texts
eye 158
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We study the scaling between bulge magnitude and central black hole (BH) mass in galaxies with virial BH masses < 10^6 solar mass. Based on careful image decomposition of a snapshot Hubble Space Telescope I-band survey, we found that these BHs are found predominantly in galaxies with pseudobulges. Here we show that the \mbulge\ relation for the pseudobulges at low mass is significantly different from classical bulges with BH masses >10^7 solar mass. Specfically, bulges span a much wider...
Source: http://arxiv.org/abs/1107.4103v2
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Sep 24, 2013
09/13
by
Jenny E. Greene; Nadia L. Zakamska; Paul S. Smith
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eye 64
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SDSS J1356+1026 is a pair of interacting galaxies at redshift z=0.123 that hosts a luminous obscured quasar in its northern nucleus. Here we present two long-slit Magellan LDSS-3 spectra that reveal a pair of symmetric ~10 kpc-size outflows emerging from this nucleus, with observed expansion velocities of ~250 km/s in projection. We present a kinematic model of these outflows and argue that the deprojected physical velocities of expansion are likely ~1000 km/s and that the kinetic energy of the...
Source: http://arxiv.org/abs/1112.3358v1
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Sep 18, 2013
09/13
by
Jenny E. Greene; Luis C. Ho; James S. Ulvestad
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We present 6 cm Very Large Array observations of the Greene & Ho (2004) sample of 19 low-mass active galaxies with high accretion rates. This is one of the only studies of a uniform sample of narrow-line Seyfert 1 (NLS1) galaxies with such high sensitivity and resolution. Although we detect only one source, the entire sample is very radio-quiet down to strong limits. GH10 was found to have a radio power of 8.5 x 10^21 W/Hz, and a ratio R = f(6 cm)/f(4400 A) of 2.8. The 3 sigma upper limits...
Source: http://arxiv.org/abs/astro-ph/0509198v1
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4.0
Jun 29, 2018
06/18
by
Ai-Lei Sun; Jenny E. Greene; Nadia L. Zakamska
texts
eye 4
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To study the impact of active galactic nuclei (AGN) feedback on the galactic ISM, we present Magellan long-slit spectroscopy of 12 luminous nearby type 2 AGN (L_bol~10^{45.0-46.5} erg/s, z~0.1). These objects are selected from a parent sample of spectroscopically identified AGN to have high [OIII]{\lambda}5007 and WISE mid-IR luminosities and extended emission in the SDSS r-band images, suggesting the presence of extended [OIII]{\lambda}5007 emission. We find spatially resolved [OIII] emission...
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1611.04469
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Sep 23, 2013
09/13
by
Louis-Benoit Desroches; Jenny E. Greene; Luis C. Ho
texts
eye 48
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We present X-ray properties of optically-selected intermediate-mass (~10^5--10^6 M_Sun) black holes (BHs) in active galaxies (AGNs), using data from the Chandra X-Ray Observatory. Our observations are a continuation of a pilot study by Greene & Ho (2007). Of the 8 objects observed, 5 are detected with X-ray luminosities in the range L_0.5-2 keV = 10^41--10^43 erg s^-1, consistent with the previously observed sample. Objects with enough counts to extract a spectrum are well fit by an...
Source: http://arxiv.org/abs/0903.2257v1
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47
Sep 21, 2013
09/13
by
Yue Shen; Xin Liu; Jenny E. Greene; Michael A. Strauss
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eye 47
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(Abridged) Approximately 1% of low redshift (z
Source: http://arxiv.org/abs/1011.5246v2
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113
Sep 17, 2013
09/13
by
Xin Liu; Jenny E. Greene; Yue Shen; Michael A. Strauss
texts
eye 113
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We report the discovery of four kpc-scale binary AGNs. These objects were originally selected from the Sloan Digital Sky Survey based on double-peaked [O III] 4959,5007 emission lines in their fiber spectra. The double peaks could result from pairing active supermassive black holes (SMBHs) in a galaxy merger, or could be due to bulk motions of narrow-line region gas around a single SMBH. Deep near-infrared (NIR) images and optical slit spectra obtained from the Magellan 6.5 m and the APO 3.5 m...
Source: http://arxiv.org/abs/1003.3467v2
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47
Sep 22, 2013
09/13
by
Xin Liu; Yue Shen; Michael A. Strauss; Jenny E. Greene
texts
eye 47
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We present a sample of 167 type 2 AGNs with double-peaked [O III] 4959,5007 narrow emission lines, selected from the Seventh Data Release of the Sloan Digital Sky Survey. The double-peaked profiles can be well modeled by two velocity components, blueshifted and redshifted from the systemic velocity. Half of these objects have a more prominent redshifted component. In cases where the H-beta emission line is strong, it also shows two velocity components whose line-of-sight (LOS) velocity offsets...
Source: http://arxiv.org/abs/0908.2426v2
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3.0
Jun 29, 2018
06/18
by
Vivienne F. Baldassare; Amy E. Reines; Elena Gallo; Jenny E. Greene
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eye 3
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We present new Chandra X-ray Observatory and Hubble Space Telescope observations of eight optically selected broad-line AGN candidates in nearby dwarf galaxies ($z
Topics: Astrophysics, High Energy Astrophysical Phenomena, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1609.07148
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3.0
Jun 30, 2018
06/18
by
R. Scott Barrows; Julia M. Comerford; Jenny E. Greene; David Pooley
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eye 3
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Galaxy mergers are likely to play a role in triggering active galactic nuclei (AGN), but the conditions under which this process occurs are poorly understood. In Paper I, we constructed a sample of spatially offset X-ray AGN that represent galaxy mergers hosting a single AGN. In this paper, we use our offset AGN sample to constrain the parameters that affect AGN observability in galaxy mergers. We also construct dual AGN samples with similar selection properties for comparison. We find that the...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1703.06143
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6.0
Jun 29, 2018
06/18
by
R. Scott Barrows; Julia M. Comerford; Jenny E. Greene; David Pooley
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We present a sample of 18 optically-selected and X-ray detected spatially offset active galactic nuclei (AGN) from the Sloan Digital Sky Survey (SDSS). In 9 systems, the X-ray AGN is spatially offset from the galactic stellar core that is located within the 3'' diameter SDSS spectroscopic fiber. In 11 systems, the X-ray AGN is spatially offset from a stellar core that is located outside the fiber, with an overlap of 2. To build the sample, we cross-matched Type II AGN selected from the SDSS...
Topics: Astrophysics, Cosmology and Nongalactic Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1606.01253
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4.0
Jun 29, 2018
06/18
by
Kevin N. Hainline; Amy E. Reines; Jenny E. Greene; Daniel Stern
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Searching for active galactic nuclei (AGN) in dwarf galaxies is important for our understanding of the seed black holes that formed in the early Universe. Here, we test infrared selection methods for AGN activity at low galaxy masses. Our parent sample consists of ~18,000 nearby dwarf galaxies (M* < 3 x 10^9 Msun, $z
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1609.06721
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75
Sep 18, 2013
09/13
by
Jenny E. Greene; Nadia L. Zakamska; Luis C. Ho; Aaron J. Barth
texts
eye 75
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We use spatially resolved long-slit spectroscopy from Magellan to investigate the extent, kinematics, and ionization structure in the narrow-line regions of 15 luminous, obscured quasars with z
Source: http://arxiv.org/abs/1102.2913v1
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Sep 23, 2013
09/13
by
Kevin N. Hainline; Alice E. Shapley; Jenny E. Greene; Charles C. Steidel
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eye 52
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We present new results for a sample of 33 narrow-lined UV-selected active galactic nuclei (AGNs), identified in the course of a spectroscopic survey for star-forming galaxies at z ~ 2-3. The rest-frame UV composite spectrum for our AGN sample shows several emission lines characteristic of AGNs, as well as interstellar absorption features seen in star-forming Lyman Break Galaxies (LBGs). We report a detection of NIV]1486, which has been observed in high-redshift radio galaxies, as well as in...
Source: http://arxiv.org/abs/1012.0075v2
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81
Sep 22, 2013
09/13
by
Luis C. Ho; Jenny E. Greene; Alexei V. Filippenko; Wallace L. W. Sargent
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eye 81
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We present new central stellar velocity dispersion measurements for 428 galaxies in the Palomar spectroscopic survey of bright, northern galaxies. Of these, 142 have no previously published measurements, most being relatively late-type systems with low velocity dispersions ( < 100 km/s). We provide updates to a number of literature dispersions with large uncertainties. Our measurements are based on a direct pixel-fitting technique that can accommodate composite stellar populations by...
Source: http://arxiv.org/abs/0906.4105v1
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5.0
Jun 30, 2018
06/18
by
Ai-Lei Sun; Jenny E. Greene; Nadia L. Zakamska; Nicole P. H. Nesvadba
texts
eye 5
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We present Atacama Large Millimeter/Submillimeter Array (ALMA) CO (1-0) and CO (3-2) observations of SDSS J135646.10+102609.0, an obscured quasar and ultra-luminous infrared galaxy (ULIRG) with two merging nuclei and a known 20-kpc-scale ionized outflow. The total molecular gas mass is M_{mol} ~ 9^{+19}_{-6} x 10^8 Msun, mostly distributed in a compact rotating disk at the primary nucleus (M_{mol} ~ 3 x 10^8 Msun) and an extended tidal arm (M_{mol} ~ 5 x 10^8 Msun). The tidal arm is one of the...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1406.4520
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Sep 20, 2013
09/13
by
Luis C. Ho; Paolo Goldoni; Xiao-Bo Dong; Jenny E. Greene; Gabriele Ponti
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eye 49
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The X-shooter instrument on the VLT was used to obtain spectra of seven moderate-redshift quasars simultaneously covering the spectral range 3000 Ang to 2.5 microns. At z ~ 1.5, most of the prominent broad emission lines in the ultraviolet to optical region are captured in their rest frame. We use this unique dataset, which mitigates complications from source variability, to intercompare the line profiles of C IV 1549, C III] 1909, Mg II 2800, and Halpha and evaluate their implications for...
Source: http://arxiv.org/abs/1205.3224v1
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Sep 23, 2013
09/13
by
Jenny E. Greene; Jeremy D. Murphy; Julia M. Comerford; Karl Gebhardt; Joshua J. Adams
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eye 69
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We use the Mitchell Spectrograph (formerly VIRUS-P) on the McDonald Observatory 2.7m Harlan J. Smith Telescope to search for the chemical signatures of massive elliptical galaxy assembly. The Mitchell Spectrograph is an integral-field spectrograph with a uniquely wide field of view (107x107 sq arcsec), allowing us to achieve remarkably high signal-to-noise ratios of ~20-70 per pixel in radial bins of 2-2.5 times the effective radii of the eight galaxies in our sample. Focusing on a sample of...
Source: http://arxiv.org/abs/1202.4464v1
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160
Jul 20, 2013
07/13
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Yan-Fei Jiang; Jenny E. Greene; Luis C. Ho; Ting Xiao; Aaron J. Barth
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eye 160
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Using HST observations of 147 host galaxies of low-mass black holes (BHs), we systematically study the structures and scaling relations of these active galaxies. Our sample is selected to have central BHs with virial masses ~10^5-10^6 solar mass. The host galaxies have total I-band magnitudes of -23.2
Source: http://arxiv.org/abs/1107.4105v2
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3.0
Jun 30, 2018
06/18
by
Jenny E. Greene; David Pooley; Nadia L. Zakamska; Julia M. Comerford; Ai-Lei Sun
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eye 3
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We present observations of extended, 20-kpc scale soft X-ray gas around a luminous obscured quasar hosted by an ultra-luminous infrared galaxy caught in the midst of a major merger. The extended X-ray emission is well fit as a thermal gas with a temperature of kT ~ 280 eV and a luminosity of L_X ~ 10^42 erg/s and is spatially coincident with a known ionized gas outflow. Based on the X-ray luminosity, a factor of ~10 fainter than the [OIII] emission, we conclude that the X-ray emission is either...
Topics: Astrophysics of Galaxies, Astrophysics, Cosmology and Nongalactic Astrophysics
Source: http://arxiv.org/abs/1404.4875
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49
Sep 21, 2013
09/13
by
Guilin Liu; Nadia L. Zakamska; Jenny E. Greene; Nicole P. H. Nesvadba; Xin Liu
texts
eye 49
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Black hole feedback -- the strong interaction between the energy output of supermassive black holes and their surrounding environments -- is routinely invoked to explain the absence of overly luminous galaxies, the black hole vs. bulge correlations and the similarity of black hole accretion and star formation histories. Yet direct probes of this process in action are scarce and limited to small samples of active nuclei. We present Gemini IFU observations of the distribution of ionized gas...
Source: http://arxiv.org/abs/1301.1677v1
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Sep 21, 2013
09/13
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Yue Shen; Jenny E. Greene; Michael A. Strauss; Gordon T. Richards; Donald P. Schneider
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eye 61
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We compile black hole (BH) masses for $\sim 60,000$ quasars in the redshift range $0.1 \lesssim z \lesssim 4.5$ included in the Fifth Data Release of the Sloan Digital Sky Survey (SDSS), using virial BH mass estimators based on the \hbeta, \MgII, and \CIV emission lines. We find that: (1) within our sample, the widths of the three lines follow log-normal distributions, with means and dispersions that do not depend strongly on luminosity or redshift;(2) the \MgII- and \hbeta-estimated BH masses...
Source: http://arxiv.org/abs/0709.3098v2
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Sep 18, 2013
09/13
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Xin Liu; Francesca Civano; Yue Shen; Paul J. Green; Jenny E. Greene; Michael A. Strauss
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eye 37
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Kiloparsec-scale binary active galactic nuclei (AGNs) signal active supermassive black hole (SMBH) pairs in merging galaxies. Despite their significance, unambiguously confirmed cases remain scarce and most have been discovered serendipitously. In a previous systematic search, we optically identified four kpc-scale binary AGNs from candidates selected with double-peaked narrow emission lines at redshifts of 0.1--0.2. Here we present Chandra and Hubble Space Telescope Wide Field Camera 3 (WFC3)...
Source: http://arxiv.org/abs/1209.5418v2
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7.0
Jun 29, 2018
06/18
by
Rachael M. Alexandroff; Nadia L. Zakamska; Sjoert van Velzen; Jenny E. Greene; Michael A. Strauss
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eye 7
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We study the radio properties of moderately obscured quasars over a range of redshifts to understand the role of radio activity in accretion using the Jansky Very Large Array (JVLA) at 6.0GHz and 1.4GHz. Our z~2.5 sample consists of optically-selected obscured quasar candidates, all of which are radio-quiet, with typical radio luminosities of $\nu L_{\nu}$[1.4 GHz] < $10^{40}$ erg s$^{-1}$. Only a single source is individually detected in our deep (rms~10 $\mu$Jy) exposures. This population...
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1603.07325
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4.0
Jun 30, 2018
06/18
by
Jenny E. Greene; Anil Seth; Mariya Lyubenova; Jonelle Walsh; Glenn van de Ven; Ronald Laesker
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We explore the warm molecular and ionized gas in the centers of two megamaser disk galaxies using K-band spectroscopy. Our ultimate goal is to determine how gas is funneled onto the accretion disk, here traced by megamaser spots on sub-pc scales. We present NIR IFU data with a resolution of ~50 pc for two galaxies: NGC 4388 with VLT/SINFONI and NGC 1194 with Keck/OSIRIS+AO. The high spatial resolution and rich spectral diagnostics allow us to study both the stellar and gas kinematics as well as...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1405.1430
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8.0
Jun 29, 2018
06/18
by
Lile Wang; Jenny E. Greene; Wenhua Ju; Roman R. Rafikov; John J. Ruan; Donald P. Schneider
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Supermassive black hole binaries (SMBHs) are expected to result from galaxy mergers, and thus are natural byproducts (and probes) of hierarchical structure formation in the Universe. They are also the primary expected source of low-frequency gravitational wave emission. We search for binary BHs using time-variable velocity shifts in broad Mg II emission lines of quasars with multi-epoch observations. First, we inspect velocity shifts of the binary SMBH candidates identified in Ju et al. (2013),...
Topics: Astrophysics, Cosmology and Nongalactic Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1611.00039
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18
Jun 28, 2018
06/18
by
Francisco Müller-Sanchez; Julia M. Comerford; Rebecca Nevin; R. Scott Barrows; Michael C. Cooper; Jenny E. Greene
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eye 18
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We have examined a subset of 18 active galactic nuclei (AGNs) drawn from a sample of 81 galaxies that possess double-peaked narrow optical emission line spectra in the Sloan Digital Sky Survey, have two optical AGN emission components separated by >0.2", and are detected in the Faint Images of the Radio Sky at Twenty-centimeters survey. Without follow-up observations, the sources of the double-peaked narrow emission lines are uncertain, and may be produced by kpc-scale separation dual...
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1509.04291
4
4.0
Jun 29, 2018
06/18
by
Remco C. E. van den Bosch; Jenny E. Greene; James A. Braatz; Anca Constantin; Cheng-Yu Kuo
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eye 4
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Megamaser disks provide the most precise and accurate extragalactic supermassive black hole masses. Here we describe a search for megamasers in nearby galaxies using the Green Bank Telescope (GBT). We focus on galaxies where we believe that we can resolve the gravitational sphere of influence of the black hole and derive a stellar or gas dynamical measurement with optical or NIR observations. Since there are only a handful of super massive black holes (SMBH) that have direct black hole mass...
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1601.00645
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6.0
Jun 29, 2018
06/18
by
Jinyi Shangguan; Xin Liu; Luis C. Ho; Yue Shen; Chien Y. Peng; Jenny E. Greene; Michael A. Strauss
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eye 6
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Binary active galactic nuclei (AGNs) provide clues to how gas-rich mergers trigger and fuel AGNs and how supermassive black hole (SMBH) pairs evolve in a gas-rich environment. While significant effort has been invested in their identification, the detailed properties of binary AGNs and their host galaxies are still poorly constrained. In a companion paper, we examined the nature of ionizing sources in the double nuclei of four kpc-scale binary AGNs with redshifts between 0.1~0.2. Here, we...
Topics: Astrophysics, High Energy Astrophysical Phenomena, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1603.07925
4
4.0
Jun 30, 2018
06/18
by
Chung-Pei Ma; Jenny E. Greene; Nicholas McConnell; Ryan Janish; John P. Blakeslee; Jens Thomas; Jeremy D. Murphy
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eye 4
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Massive early-type galaxies represent the modern-day remnants of the earliest major star formation episodes in the history of the universe. These galaxies are central to our understanding of the evolution of cosmic structure, stellar populations, and supermassive black holes, but the details of their complex formation histories remain uncertain. To address this situation, we have initiated the MASSIVE Survey, a volume-limited, multi-wavelength, integral-field spectroscopic (IFS) and photometric...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1407.1054
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7.0
Jun 30, 2018
06/18
by
Brendan P. Miller; Elena Gallo; Jenny E. Greene; Brandon C. Kelly; Tommaso Treu; Jong-Hak Woo; Vivienne Baldassare
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eye 7
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Distinct seed formation mechanisms are imprinted upon the fraction of dwarf galaxies currently containing a central supermassive black hole. Seeding by Pop III remnants is expected to produce a higher occupation fraction than is generated with direct gas collapse precursors. Chandra observations of nearby early-type galaxies can directly detect even low-level supermassive black hole activity, and the active fraction immediately provides a firm lower limit to the occupation fraction. Here, we...
Topics: Astrophysics of Galaxies, Astrophysics, Cosmology and Nongalactic Astrophysics
Source: http://arxiv.org/abs/1403.4246
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59
Sep 23, 2013
09/13
by
Nicholas J. McConnell; Shi-Fan S. Chen; Chung-Pei Ma; Jenny E. Greene; Tod R. Lauer; Karl Gebhardt
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eye 59
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We have tested the effect of spatial gradients in stellar mass-to-light ratio (Y) on measurements of black hole masses (MBH) derived from stellar orbit superposition models. Such models construct a static gravitational potential for a galaxy and its central black hole, but typically assume spatially uniform Y. We have modeled three giant elliptical galaxies with gradients alpha = d(log Y)/d(log r) from -0.2 to +0.1. Color and line strength gradients suggest mildly negative alpha in these...
Source: http://arxiv.org/abs/1303.4393v1
