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Discovery of two spectroscopically peculiar, low-luminosity quasars at z ~ 4

Glikman, Eilat and Djorgovski, S. G. and Stern, Daniel and Bogosavljević, Milan and Mahabal, Ashish (2007) Discovery of two spectroscopically peculiar, low-luminosity quasars at z ~ 4. Astrophysical Journal Letters, 663 (2). L73-L76. ISSN 2041-8205. https://resolver.caltech.edu/CaltechAUTHORS:20090409-153118437

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Abstract

We report the discovery of two low-luminosity quasars at z ~ 4, both of which show prominent N iv] λ1486 emission. This line is extremely rare in quasar spectra at any redshift; detecting it in two of a sample of 23 objects (i.e., ~9% of the sample) is intriguing and is likely due to the low-luminosity, high-redshift quasar sample we are studying. This is still a poorly explored regime, where contributions from associated, early starbursts may be significant. One interpretation of this line posits photoionization by very massive young stars. Seeing N iv] λ1486 emission in a high-redshift quasar may thus be understood in the context of coformation and early coevolution of galaxies and their supermassive black holes. Alternatively, we may be seeing a phenomenon related to the early evolution of quasar broad emission line regions. The nondetection (and possibly even broad absorption) of N v λ1240 line in the spectrum of one of these quasars may support that interpretation. These two objects may signal a new faint quasar population or an early AGN evolutionary stage at high redshifts.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1086/520085DOIArticle
ORCID:
AuthorORCID
Glikman, Eilat0000-0003-0489-3750
Djorgovski, S. G.0000-0002-0603-3087
Stern, Daniel0000-0003-2686-9241
Mahabal, Ashish0000-0003-2242-0244
Additional Information:© 2007 American Astronomical Society. Print publication: Issue 2 (2007 July 10); received 2007 April 30; accepted for publication 2007 May 24; published 2007 June 28. We thank the referee for helpful feedback. We are grateful to the staff of W. M. Keck observatory for their assistance during our observing runs. This work was supported in part by the NSF grant AST 04-07448, and by the Ajax foundation. The work of D. S. was carried out at Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA.
Group:Infrared Processing and Analysis Center (IPAC)
Funders:
Funding AgencyGrant Number
NSFAST 04-07448
Ajax FoundationUNSPECIFIED
NASA/JPL/CaltechUNSPECIFIED
Subject Keywords:galaxies: evolution; quasars: emission lines; quasars: general
Issue or Number:2
Record Number:CaltechAUTHORS:20090409-153118437
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20090409-153118437
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:13915
Collection:CaltechAUTHORS
Deposited By: Jason Perez
Deposited On:17 Apr 2009 15:56
Last Modified:09 Mar 2020 13:18

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