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104. Quasar complexity simplified: an analysis of a sample comprising some 20,000 mass-accreting supermassive black holes, known as quasars, shows that most of the diverse properties of these cosmic beacons are explained by only two quantities

Author

Brotherton, Michael S.

Subjects
Light -- Observations, Jets -- Observations, Quasars -- Observations -- Properties, Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

If a picture is worth a thousand words, then a spectrum can be worth a thousand pictures. That is perhaps an underestimate when dealing with star-like blobs of light that [...]

Published
2014

109. Hubble Space Telescope Ultraviolet Spectroscopy of Fourteen Low-Redshift Quasars

Author

Ganguly, Rajib, Brotherton, Michael S., Arav, Nahum, Heap, Sara R., Wisotzki, Lutz, Aldcroft, Thomas L., Alloin, Danielle, Behar, Ehud, Canalizo, Gabriela, Crenshaw, D. Michael, de Kool, Martijn, Chambers, Kenneth, Cecil, Gerald, Chatzichristou, Eleni, Everett, John, Gabel, Jack, Gaskell, C. Martin, Galliano, Emmanuel, Green, Richard F., Hall, Patrick B., Hines, Dean C., Junkkarinen, Vesa T., Kaastra, Jelle S., Kaiser, Mary Elizabeth, Kazanas, Demosthenes, Konigl, Arieh, Korista, Kirk T., Kriss, Gerard A., Laor, Ari, Leighly, Karen M., Mathur, Smita, Ogle, Patrick, Proga, Daniel, Sabra, Bassem, Sivron, Ran, Snedden, Stephanie, Telfer, Randal, and Vestergaard, Marianne

Subjects
astro-ph, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

We present low-resolution ultraviolet spectra of 14 low redshift (z1.4 Large Bright Quasar samples. By design, our objects sample luminosities in between these two surveys, and our four absorbed objects are consistent with the v ~ L^0.62 relation derived by Laor & Brandt (2002). Another quasar, HE0441-2826, contains extremely weak emission lines and our spectrum is consistent with a simple power-law continuum. The quasar is radio-loud, but has a steep spectral index and a lobe-dominated morphology, which argues against it being a blazar. The unusual spectrum of this quasar resembles the spectra of the quasars PG1407+265, SDSSJ1136+0242, and PKS1004+13 for which several possible explanations have been entertained., Uses aastex.cls, 21 pages in preprint mode, including 6 figures and 2 tables; accepted for publication in The Astronomical Journal (projected vol 133)

Published
2007

110. Hubble Space Telescope Ultraviolet Spectroscopy of 14 Low-Redshift Quasars

Author

Junkkarinen, Vesa T., Michael Crenshaw, D., Proga, Daniel, Aldcroft, Thomas L., Canalizo, Gabriela, Heap, Sara R., Ogle, Patrick, Kazanas, Demosthenes, Konigl, Arieh, Leighly, Karen M., Galliano, Emmanuel, Brotherton, Michael S., Alloin, Danielle, Kriss, Gerard A., Korista, Kirk T., Gabel, Jack, Cecil, Gerald, Hines, Dean C., Kaastra, Jelle S., Sivron, Ran, Snedden, Stephanie, Kaiser, Mary Elizabeth, Arav, Nahum, Evererr, John, Vestergaard, Marianne, Chambers, Kenneth, Behar, Ehud, Martin Gaskell, C., De Kool, Martijn, Mathur, Smita, Wisotzki, Lutz, Sabra, Bassem, Telfer, Randal, Chatzichristou, Eleni, Ganguly, Rajib, Laor, Ari, Green, Richard F., and Hall, Patrick B.

Abstract

133

Published
2007
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111. XMM-Newton detection of the rare Fanaroff-Riley type II broad absorption line quasar first J101614.3+520916

Author

Schaefer, Justin J., Brotherton, Michael S., Shang, Zhaohui, Gregg, Michael D., Becker, Robert H., Laurent-Muehleisen, Sally A., Lacy, Mark, and White, Richard L.

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Cosmology and Extragalactic Astrophysics, Caltech Library Services
Abstract

We have detected FIRST J101614.3+520916 with the XMM-Newton X-ray observatory. FIRST J101614.3+520916, one of the most extreme radio-loud, broad absorption line (BAL) quasars so far discovered, is also a Fanaroff-Riley type II radio source. We find that, compared to its estimated intrinsic X-ray flux, the observed X-rays are likely suppressed and that the observed hardness ratio indicates significant soft X-ray photons. This is inconsistent with the simplest model, a normal quasar spectrum absorbed by a large neutral H I column density, which would primarily absorb the softer photons. More complex models, involving partial covering, an ionized absorber, ionized mirror reflection, or jet contributions need to be invoked to explain this source. The suppressed but soft X-ray emission in this radio-loud BAL quasar is consistent with the behavior displayed by other BAL quasars, both radio-loud and radio-quiet.

Published
2006

113. How similar are the properties of quasars with nearly identical ultraviolet spectra?

Author

Rochais, Thomas, Singh, Vikram, Chick, William, Maithil, Jaya, Sutter, Jessica, Brotherton, Michael S., and Zhaohui Shang

Subjects
SPECTRA of quasars, ULTRAVIOLET astronomy, DOPPELGANGERS, METAPHYSICAL cosmology, BINARY black holes
Abstract

The spectrum of a quasar contains important information about its properties. Thus, it can be expected that two quasars with similar spectra will have similar properties, but just how similar has not before been quantified. Here we compare the ultraviolet spectra of a sample of 5553 quasars from Data Release 7 of the Sloan Digital Sky Survey, focusing on the 1350 Å ≤λ ≤ 2900 Å rest-frame region which contains prominent emission lines from Si IV, OIV], CIV, C III], and MgII species.We use principal component analysis to determine the dominant components of spectral variation, as well as to quantitatively measure spectral similarity. As suggested by both the Baldwin effect and modified Baldwin effect, quasars with similar spectra have similar properties: bolometric luminosity, Eddington fraction, and black hole mass. The latter two quantities are calculated from the luminosity in conjunction with spectral features, and the variation between quasars with virtually identical spectra (which we call doppelgangers) is driven by the variance in the luminosity plus measurement uncertainties. In the doppelgangers the luminosity differences show 1σ uncertainties of 57 per cent (or 0.63 mag) and ~70 per cent 1σ uncertainties for mass and Eddington fraction. Much of the difference in luminosities may be attributable to time lags between the spectral lines and the continuum. Furthermore, we find that suggestions that the mostly highly accreting quasars should be better standard candles than other quasars are not borne out for doppelgangers. Finally, we discuss the implications for using quasars as cosmological probes and the nature of the first two spectral principal components. [ABSTRACT FROM AUTHOR]

Published
2017
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115. The X-ray spectrum and spectral energy distribution of FIRST J155633.8+351758: a LoBAL quasar with a probable polar outflow

Author

Berrington, Robert C., primary, Brotherton, Michael S., additional, Gallagher, Sarah C., additional, Ganguly, Rajib, additional, Shang, Zhaohui, additional, DiPompeo, Michael, additional, Chatterjee, Ritaban, additional, Lacy, Mark, additional, Gregg, Michael D., additional, Hall, Patrick B., additional, and Laurent-Muehleisen, S. A., additional

Published
2013
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117. HUBBLE SPACE TELESCOPE ULTRAVIOLET SPECTROSCOPY OF 14 LOW-REDSHIFT QUASARS

Author

Ganguly, Rajib, Brotherton, Michael S., Arav, Nahum, Heap, Sara R., Wisotzki, Lutz, Aldcroft, Thomas L., Alloin, Danielle, Behar, Ehud, Canalizo, Gabriela, Crenshaw, D. Michael, De Kool, Martijn, Chambers, Kenneth, Cecil, Gerald, Chatzichristou, Eleni, Everett, John, Gabel, Jack R., Gaskell, C. Martin, Galliano, Emmanuel, Green, Richard F., Hall, Patrick B., Hines, Dean C., Junkkarinen, Vesa T., Kaastra, Jelle S., Kaiser, Mary Elizabeth, Kazanas, Demosthenes, Konigl, Arieh, Korista, Kirk T., Kriss, Gerard A., Laor, Ari, Leighly, Karen M., Mathur, Smita, Ogle, Patrick, Proga, Daniel, Sabra, Bassem, Sivron, Ran, Snedden, Stephanie A., Telfer, Randal, Vestergaard, Marianne, Ganguly, Rajib, Brotherton, Michael S., Arav, Nahum, Heap, Sara R., Wisotzki, Lutz, Aldcroft, Thomas L., Alloin, Danielle, Behar, Ehud, Canalizo, Gabriela, Crenshaw, D. Michael, De Kool, Martijn, Chambers, Kenneth, Cecil, Gerald, Chatzichristou, Eleni, Everett, John, Gabel, Jack R., Gaskell, C. Martin, Galliano, Emmanuel, Green, Richard F., Hall, Patrick B., Hines, Dean C., Junkkarinen, Vesa T., Kaastra, Jelle S., Kaiser, Mary Elizabeth, Kazanas, Demosthenes, Konigl, Arieh, Korista, Kirk T., Kriss, Gerard A., Laor, Ari, Leighly, Karen M., Mathur, Smita, Ogle, Patrick, Proga, Daniel, Sabra, Bassem, Sivron, Ran, Snedden, Stephanie A., Telfer, Randal, and Vestergaard, Marianne

Abstract

We present low-resolution ultraviolet spectra of 14 low-redshift (zem ≤ 0:8) quasars observed with the Hubble Space Telescope STIS as part of a Snapshot project to understand the relationship between quasar outflows and luminosity. By design, all observations cover the C iv emission line. Ten of the quasars are from the Hamburg-ESO catalog, three are from the Palomar-Green catalog, and one is from the Parkes catalog. The sample contains a few interesting quasars, including two broad absorption line (BAL) quasars (HE 0143-3535 and HE 0436-2614), one quasar with a mini-BAL (HE 1105-0746), and one quasar with associated narrow absorption (HE 0409-5004). These BAL quasars are among the brightest known (although not the most luminous) since they lie at zem < 0.8. We compare the properties of these BAL quasars to the zem < 0.5 Palomar-Green and zem > 1.4 Large Bright Quasar Survey samples. By design, our objects sample luminosities in between these two surveys, and our four absorbed objects are consistent with the ν ~ L0.62 relation derived by Laor & Brandt (2002). Another quasar, HE 0441-2826, contains extremely weak emission lines, and our spectrum is consistent with a simple power-law continuum. The quasar is radio-loud but has a steep spectral index and a lobe-dominated morphology, which argues against it being a blazar. The unusual spectrum of this quasar resembles the spectra of the quasars PG 1407+265, SDSS J1136+0242, and PKS 1004+13, for which several possible explanations have been entertained.

Published
2007

118. THE PROPERTIES OF POST-STARBURST QUASARS BASED ON OPTICAL SPECTROSCOPY

Author

Cales, Sabrina L., primary, Brotherton, Michael S., additional, Shang, Zhaohui, additional, Runnoe, Jessie C., additional, DiPompeo, Michael A., additional, Bennert, Vardha Nicola, additional, Canalizo, Gabriela, additional, Hiner, Kyle D., additional, Stoll, R., additional, Ganguly, Rajib, additional, and Diamond-Stanic, Aleksandar, additional

Published
2012
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124. THE NEXT GENERATION ATLAS OF QUASAR SPECTRAL ENERGY DISTRIBUTIONS FROM RADIO TO X-RAYS

Author

Shang, Zhaohui, primary, Brotherton, Michael S., additional, Wills, Beverley J., additional, Wills, D., additional, Cales, Sabrina L., additional, Dale, Daniel A., additional, Green, Richard F., additional, Runnoe, Jessie C., additional, Nemmen, Rodrigo S., additional, Gallagher, Sarah C., additional, Ganguly, Rajib, additional, Hines, Dean C., additional, Kelly, Benjamin J., additional, Kriss, Gerard A., additional, Li, Jun, additional, Tang, Baitian, additional, and Xie, Yanxia, additional

Published
2011
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130. Hubble Space TelescopeUltraviolet Spectroscopy of 14 Low-Redshift Quasars

Author

Ganguly, Rajib, primary, Brotherton, Michael S., additional, Arav, Nahum, additional, Heap, Sara R., additional, Wisotzki, Lutz, additional, Aldcroft, Thomas L., additional, Alloin, Danielle, additional, Behar, Ehud, additional, Canalizo, Gabriela, additional, Crenshaw, D. Michael, additional, de Kool, Martijn, additional, Chambers, Kenneth, additional, Cecil, Gerald, additional, Chatzichristou, Eleni, additional, Everett, John, additional, Gabel, Jack, additional, Gaskell, C. Martin, additional, Galliano, Emmanuel, additional, Green, Richard F., additional, Hall, Patrick B., additional, Hines, Dean C., additional, Junkkarinen, Vesa T., additional, Kaastra, Jelle S., additional, Kaiser, Mary Elizabeth, additional, Kazanas, Demosthenes, additional, Konigl, Arieh, additional, Korista, Kirk T., additional, Kriss, Gerard A., additional, Laor, Ari, additional, Leighly, Karen M., additional, Mathur, Smita, additional, Ogle, Patrick, additional, Proga, Daniel, additional, Sabra, Bassem, additional, Sivron, Ran, additional, Snedden, Stephanie, additional, Telfer, Randal, additional, and Vestergaard, Marianne, additional

Published
2007
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132. Quasars and the Big Blue Bump

Author

Shang, Zhaohui, primary, Brotherton, Michael S., additional, Green, Richard F., additional, Kriss, Gerard A., additional, Scott, Jennifer, additional, Quijano, Jessica Kim, additional, Blaes, Omer, additional, Hubeny, Ivan, additional, Hutchings, John, additional, Kaiser, Mary Elizabeth, additional, Koratkar, Anuradha, additional, Oegerle, William, additional, and Zheng, Wei, additional

Published
2005
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133. The Black Hole–Bulge Relationship in Quasars

Author

Shields, Gregory A., primary, Gebhardt, Karl, additional, Salviander, Sarah, additional, Wills, Beverley J., additional, Xie, Bingrong, additional, Brotherton, Michael S., additional, Yuan, Juntao, additional, and Dietrich, Matthias, additional

Published
2003
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137. The Reddest Quasars

Author

Gregg, Michael D., primary, Lacy, Mark, additional, White, Richard L., additional, Glikman, Eilat, additional, Helfand, David, additional, Becker, Robert H., additional, and Brotherton, Michael S., additional

Published
2002
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138. The FIRST Bright Quasar Survey. III. The South Galactic Cap

Author

Becker, Robert H., primary, White, Richard L., additional, Gregg, Michael D., additional, Laurent‐Muehleisen, Sally A., additional, Brotherton, Michael S., additional, Impey, Chris D., additional, Chaffee, Frederic H., additional, Richards, Gordon T., additional, Helfand, David J., additional, Lacy, Mark, additional, Courbin, Frederic, additional, and Proctor, Deanne D., additional

Published
2001
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144. The FIRST Bright Quasar Survey. II. 60 Nights and 1200 Spectra Later

Author

White, Richard L., primary, Becker, Robert H., additional, Gregg, Michael D., additional, Laurent‐Muehleisen, Sally A., additional, Brotherton, Michael S., additional, Impey, Chris D., additional, Petry, Catherine E., additional, Foltz, Craig B., additional, Chaffee, Frederic H., additional, Richards, Gordon T., additional, Oegerle, William R., additional, Helfand, David J., additional, McMahon, Richard G., additional, and Cabanela, Juan E., additional

Published
2000
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147. A Study of SN 1992H in NGC 5377

Author

Clocchiatti, Alejandro, primary, Benetti, Stefano, additional, Wheeler, J. Craig, additional, Wren, William, additional, Boisseau, J., additional, Cappellaro, Enrico, additional, Turatto, Massimo, additional, Patat, Ferdinando, additional, Swartz, Douglas A., additional, Harkness, Robert P., additional, Brotherton, Michael S., additional, Wills, Beverly, additional, Hemenway, Paul, additional, Cornell, Mark, additional, Frueh, Marian, additional, and Kaiser, Mary B., additional

Published
1996
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148. MID-INFRARED SPECTRAL PROPERTIES OF POST-STARBURST QUASARS.

Author

PENG WEI, ZHAOHUI SHANG, BROTHERTON, MICHAEL S., CALES, SABRINA L., HINES, DEAN C., DALE, DANIEL A., GANGULY, RAJIB, and CANALIZO, GABRIELA

Subjects
SPECTROGRAPHS, OPTICAL resolution, HHC (Computer), ACTIVE galactic nuclei, POLYCYCLIC aromatic hydrocarbons
Abstract

We present Spitzer InfraRed Spectrograph low-resolution spectra of 16 spectroscopically selected post-starburst quasars (PSQs) at z ~ 0.3. The optical spectra of these broad-lined active galactic nuclei (AGNs) simultaneously show spectral signatures of massive intermediate-aged stellar populations making them good candidates for studying the connections between AGNs and their hosts. The resulting spectra show relatively strong polycyclic aromatic hydrocarbon (PAH) emission features at 6.2 and 11.3μm and a very weak silicate feature, indicative of ongoing star formation and low dust obscuration levels for the AGNs. We find that the mid-infrared composite spectrum of PSQs has spectral properties between ULIRGs and QSOs, suggesting that PSQs are hybrid AGN and starburst systems as also seen in their optical spectra. We also find that PSQs in early-type host galaxies tend to have relatively strong AGN activities, while those in spiral hosts have stronger PAH emission, indicating more star formation. [ABSTRACT FROM AUTHOR]

Published
2013
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149. 2D stellar population and gas kinematics of the inner 1.5 kpc of the post-starburst quasar SDSS J0210-0903.

Author

Sanmartim, David, Storchi-Bergmann, Thaisa, and Brotherton, Michael S.

Subjects
STELLAR activity, TWO-dimensional models, QUASARS, GALAXIES, SCIENTIFIC observation, IONIZING radiation
Abstract

Post-starburst quasars (PSQs) are hypothesized to represent a stage in the evolution of massive galaxies in which the star formation has been recently quenched due to the feedback of the nuclear activity. In this paper, our goal is to test this scenario with a resolved stellar population study of the PSQ J0210-0903, as well as of its emitting gas kinematics and excitation. We have used optical integral field spectroscopy obtained with the Gemini Multi-Object Spectrograph instrument at a velocity resolution of 120 km s-1 and a spatial resolution of 0.5 kpc. We find that old stars dominate the luminosity (at 4700 Å) in the inner 0.3 kpc (radius), while beyond this region (at 0.8 kpc) the stellar population is dominated by both intermediate-age and young ionizing stars. The gas emission-line ratios are typical of Seyfert nuclei in the inner 0.3 kpc, where an outflow is observed. Beyond this region, the line ratios are typical of low-ionization nuclear emission-line regions and may result from the combination of diluted radiation from the nucleus and ionization from young stars. The gas kinematics show a combination of rotation in the plane of the galaxy and outflows, observed with a maximum blueshift of-670 km s-1.We have estimated a mass outflowrate in ionized gas in the range 0.3-1.1M⊙ yr-1 and a kinetic power for the outflow of Eout 1.4-5.0 × 1040 erg s-1 0.03-0.1 per cent × Lbol. This outflow rate is two orders of magnitude higher than the nuclear accretion rate of 8.7 × 10-3M⊙-yr-1, thus being the result of mass loading of the nuclear outflow by circumnuclear galactic gas. Our observations support an evolutionary scenario in which the feeding of gas to the nuclear region has triggered a circumnuclear starburst 100 Myr ago, followed by the triggering of the nuclear activity, producing the observed gas outflow which may have quenched further star formation in the inner 0.3 kpc. [ABSTRACT FROM AUTHOR]

Published
2013
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150. AGN STORM 2. VIII. Investigating the Narrow Absorption Lines in Mrk 817 Using HST-COS Observations.

Author

Dehghanian, Maryam, Arav, Nahum, Kriss, Gerard A., Mehdipour, Missagh, Byun, Doyee, Walker, Gwen, Sharma, Mayank, Barth, Aaron J., Bentz, Misty C., Boizelle, Benjamin D., Brotherton, Michael S., Cackett, Edward M., Dalla Bontà, Elena, De Rosa, Gisella, Ferland, Gary J., Fian, Carina, Filippenko, Alexei V., Gelbord, Jonathan, Goad, Michael R., and Horne, Keith

Subjects
*ACTIVE galactic nuclei, *SEYFERT galaxies, *ACTIVE galaxies, *SPACE telescopes, *SPECTROGRAPHS
Abstract

We observed the Seyfert 1 galaxy Mrk 817 during an intensive multiwavelength reverberation mapping campaign for 16 months. Here, we examine the behavior of narrow UV absorption lines seen in the Hubble Space Telescope/Cosmic Origins Spectrograph spectra, both during the campaign and in other epochs extending over 14 yr. We conclude that, while the narrow absorption outflow system (at −3750 km s−1 with FWHM = 177 km s−1) responds to the variations of the UV continuum as modified by the X-ray obscurer, its total column density (log N H = 19.5 − 0.13 + 0.61 cm−2) did not change across all epochs. The adjusted ionization parameter (scaled with respect to the variations in the hydrogen-ionizing continuum flux) is log U H = −1.0 − 0.3 + 0.1 . The outflow is located at a distance smaller than 38 pc from the central source, which implies a hydrogen density of n H > 3000 cm−3. The absorption outflow system only covers the continuum emission source and not the broad emission line region, which suggests that its transverse size is small (< 1016 cm), with potential cloud geometries ranging from spherical to elongated along the line of sight. [ABSTRACT FROM AUTHOR]

Published
2024
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