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Related papers: A Near-Infrared Spectral Template for Quasars

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We have created a variety of composite quasar spectra using a homogeneous data set of over 2200 spectra from the Sloan Digital Sky Survey (SDSS). The quasar sample spans a redshift range of 0.044 <= z <= 4.789, and an absolute r' magnitude…

Astrophysics · Physics 2008-11-26 SDSS Collaboration , Daniel E. Vanden Berk

We construct a composite quasar spectrum from 284 HST FOS spectra of 101 quasars with redshifts z > 0.33. The spectrum covers the wavelengths between 350 and 3000 A in the rest frame. There is a significant steepening of the continuum slope…

Astrophysics · Physics 2009-10-28 W. Zheng , G. A. Kriss , R. C. Telfer , J. P. Grimes , A. F. Davidsen

We present optical and near-infrared (NIR) spectroscopic observations for a sample of $45$ quasars at $6.50 < z \leq 7.64$ with absolute magnitudes at $1450$ \r{A} in the range $-28.82 \leq M_{1450} \leq -24.13$ and their composite…

We present a very high signal-to-noise ratio composite spectrum created using 657 radio-selected quasars from the FIRST Bright Quasar Survey. The spectrum spans rest-frame wavelengths 900 - 7500 Angstroms. Additionally we present composite…

We analyse a sample of 85 luminous (log(nuLnu(3\um)/erg s-1)>45.5) quasars with restframe ~2-11 \um spectroscopy from AKARI and Spitzer. Their high luminosity allows a direct determination of the near-infrared quasar spectrum free from host…

Astrophysics of Galaxies · Physics 2016-08-31 Antonio Hernán-Caballero , Evanthia Hatziminaoglou , Almudena Alonso-Herrero , Silvia Mateos

Quasi-stellar object (QSO) spectral templates are important both to QSO physics and for investigations that use QSOs as probes of intervening gas and dust. However, combinations of various QSO samples obtained at different times and with…

Astrophysics of Galaxies · Physics 2015-12-23 Jonatan Selsing , Johan P. U. Fynbo , Lise Christensen , Jens-Kristian Krogager

Mid-infrared (MIR) quasar spectra exhibit a suite of emission features including high ionization coronal lines from the narrow line region illuminated by the ionizing continuum, broad dust bumps from silicates and graphites, and polycyclic…

Astrophysics of Galaxies · Physics 2015-06-18 Allison R. Hill , S. C. Gallagher , R. P. Deo , E. Peeters , Gordon T. Richards

We present a comprehensive analysis of Chandra X-ray observations of 15 young radio quasars at redshifts $4.5 < z < 5.0$. All sources are detected in the $0.5-7.0$ keV energy band. Emission spectra are extracted, and the average photon…

The Baryon Oscillation Spectroscopic Survey (BOSS) has collected more than 150,000 $2.1 \leq z \leq 3.5$ quasar spectra since 2009. Using this unprecedented sample, we create a composite spectrum in the rest-frame of 102,150 quasar spectra…

The composite spectra of quasars are widely used as templates for redshift determination, as well as for measurements of the mean transmission in Ly\alpha-forest studies, and for investigation of general spectral properties of quasars.…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 G. Ivashchenko , O. Sergijenko , O. Torbaniuk

We have observed a sample of 15 and 8 quasars with redshifts between 0.11 and 0.87 (mean value 0.38) in the J and K' bands respectively. Eleven of the quasars were previously known to be associated with extended emission line regions. After…

Astrophysics · Physics 2009-10-31 I. Marquez , F. Durret , P. Petitjean

We present JHK near-infrared (NIR) spectroscopy of 25 candidate Type II quasars selected from the Sloan Digital Sky Survey, using Triplespec on the Apache Point Observatory 3.5m telescope, FIRE at the Magellan/Baade 6.5m telescope, and…

We present mid-infrared observations of 18 sources from a sample of 21 z~2 radio-intermediate obscured quasars. The mid-infrared spectra of the sources are continuum dominated, and 12 sources show deep silicate absorption with tau_9.7~1-2.…

Astrophysics · Physics 2009-11-13 Alejo Martinez-Sansigre , Mark Lacy , Anna Sajina , Steve Rawlings

We present optical spectra and redshift measurements for 178 flat-spectrum objects from the Parkes quarter-Jansky flat-spectrum sample. These spectra were obtained in order to compile a complete sample of quasars for use in a study of…

Astrophysics · Physics 2009-11-07 I. M. Hook , P. A. Shaver , C. A. Jackson , J. V. Wall , K. I. Kellermann

We have measured mid-infrared radiation from an orientation-unbiased sample of 3CRR galaxies and quasars at redshifts 0.4 < z < 1.2 with the IRS and MIPS instruments on the Spitzer Space Telescope. Powerful emission (L_24micron > 10^22.4…

Astrophysics · Physics 2011-02-11 K. Cleary , C. R. Lawrence , J. A. Marshall , L. Hao , D. Meier

We report an infrared 1-1.8 micron (J+H-bands), low-resolution (R=450) spectrogram of the highest-redshift radio-loud quasar currently known, SDSS J083643.85+005453.3, obtained during the spectroscopic commissioning run of the FLAMINGOS…

We determine the rest-frame 8 micron luminosity function of type I quasars over the redshift range 1<z<5. Our sample consists of 292 24 micron sources brighter than 1 mJy selected from 7.17 square degrees of the Spitzer Space Telescope MIPS…

We have obtained quasi-simultaneous ultraviolet-optical spectra for 22 out of 23 quasars in the complete PG-X-ray sample with redshift, z<0.4, and M_B<-23. The spectra cover rest-frame wavelengths from at least Lyman-alpha to H-alpha. Here…

Astrophysics · Physics 2008-11-26 Zhaohui Shang , Beverley J. Wills , D. Wills , Michael S. Brotherton

A narrowband imaging survey of 276 square minutes of arc was carried out at near infrared wavelengths to search for emission line objects at high redshifts. Most of the fields contained a known quasar or radio galaxy at a redshift that…

Astrophysics · Physics 2009-10-28 D. Thompson , F. Mannucci , S. V. W. Beckwith

We present radio spectra spanning $0.1 - 10$ GHz for the sample of heavily obscured luminous quasars with extremely red mid-infrared-optical colors and compact radio emission. The spectra are constructed from targeted 10 GHz observations…

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