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Title: iPTF Discovery of the Rapid “Turn-on” of a Luminous Quasar

Abstract

We present a radio-quiet quasar at z = 0.237 discovered "turning on" by the intermediate Palomar Transient Factory (iPTF). The transient, iPTF 16bco, was detected by iPTF in the nucleus of a galaxy with an archival Sloan Digital Sky Survey spectrum with weak narrow-line emission characteristic of a low-ionization nuclear emission-line region (LINER). Our follow-up spectra show the dramatic appearance of broad Balmer lines and a power-law continuum characteristic of a luminous ( L bol ≈ 10 45 erg s -1) type 1 quasar 12 yr later. Our photometric monitoring with PTF from 2009-2012 and serendipitous X-ray observations from the XMM-Newton Slew Survey in 2011 and 2015 constrain the change of state to have occurred less than 500 days before the iPTF detection. An enhanced broad Hα/[O iii] λ5007 line ratio in the type 1 state relative to other changing-look quasars also is suggestive of the most rapid change of state yet observed in a quasar. Here, we argue that the > 10 increase in Eddington ratio inferred from the brightening in UV and X-ray continuum flux is more likely due to an intrinsic change in the accretion rate of a preexisting accretion disk than an external mechanism such asmore » variable obscuration, microlensing, or the tidal disruption of a star. However, further monitoring will be helpful in better constraining the mechanism driving this change of state. The rapid "turn-on" of the quasar is much shorter than the viscous infall timescale of an accretion disk and requires a disk instability that can develop around a ~ 10 8 M black hole on timescales less than 1 yr.« less

Authors:
ORCiD logo [1];  [2]; ORCiD logo [3];  [4]; ORCiD logo [5]; ORCiD logo [4]; ORCiD logo [6];  [7];  [8]; ORCiD logo [9]; ORCiD logo [10]; ORCiD logo [11]; ORCiD logo [4]; ORCiD logo [9]; ORCiD logo [12];  [13]
  1. Univ. of Maryland, College Park, MD (United States). Dept. of Astronomy; Univ. of Maryland, College Park, MD (United States). Joint Space-Science Inst.
  2. Univ. of Maryland, College Park, MD (United States). Dept. of Astronomy
  3. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States); Univ. of Maryland, College Park, MD (United States). Joint Space-Science Inst.
  4. California Inst. of Technology (CalTech), Pasadena, CA (United States). Dept. of Astronomy
  5. California Inst. of Technology (CalTech), Pasadena, CA (United States). Cahill Center for Astronomy and Astrophysics, Caltech Optical Observatories; California Inst. of Technology (CalTech), Pasadena, CA (United States). Infrared Processing and Analysis Center
  6. Univ. of Oxford (United Kingdom). Dept. of Astrophysics, Dept. of Physics
  7. National Tsing Hua Univ., Hsinchu (Taiwan). Inst. of Astronomy
  8. Jodrell Bank Centre for Astrophysics, Manchester (United Kingdom)
  9. National Central Univ., Taoyuan City (Taiwan). Graduate Inst. of Astronomy
  10. Univ. of Washington, Seattle, WA (United States). eScience Inst. and Astronomy Dept.
  11. Stockholm Univ. (Sweden). Oskar Klein Center, Dept. of Astronomy
  12. Univ. of California, Berkeley, CA (United States). Dept. of Astronomy; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  13. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE Office of Science (SC); National Science Foundation (NSF); European Research Council (ERC); National Aeronautic and Space Administration (NASA)
OSTI Identifier:
1393611
Alternate Identifier(s):
OSTI ID: 1407904
Report Number(s):
LA-UR-17-27778
Journal ID: ISSN 1538-4357; ark:/13030/qt2193j6j2
Grant/Contract Number:
AC02-05CH11231; ERC-2012-StG-307215; NNX16AN85G; 1454816; AC52-06NA25396
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
The Astrophysical Journal (Online)
Additional Journal Information:
Journal Name: The Astrophysical Journal (Online); Journal Volume: 835; Journal Issue: 2; Journal ID: ISSN 1538-4357
Publisher:
Institute of Physics (IOP)
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS; accretion; accretion disks; black hole physics; galaxies; active surveys; Astronomy and Astrophysics

Citation Formats

Gezari, S., Hung, T., Cenko, S. B., Blagorodnova, N., Yan, Lin, Kulkarni, S. R., Mooley, K., Kong, A. K. H., Cantwell, T. M., Yu, P. C., Cao, Y., Fremling, C., Neill, J. D., Ngeow, C. -C., Nugent, P. E., and Wozniak, P.. iPTF Discovery of the Rapid “Turn-on” of a Luminous Quasar. United States: N. p., 2017. Web. doi:10.3847/1538-4357/835/2/144.
Gezari, S., Hung, T., Cenko, S. B., Blagorodnova, N., Yan, Lin, Kulkarni, S. R., Mooley, K., Kong, A. K. H., Cantwell, T. M., Yu, P. C., Cao, Y., Fremling, C., Neill, J. D., Ngeow, C. -C., Nugent, P. E., & Wozniak, P.. iPTF Discovery of the Rapid “Turn-on” of a Luminous Quasar. United States. doi:10.3847/1538-4357/835/2/144.
Gezari, S., Hung, T., Cenko, S. B., Blagorodnova, N., Yan, Lin, Kulkarni, S. R., Mooley, K., Kong, A. K. H., Cantwell, T. M., Yu, P. C., Cao, Y., Fremling, C., Neill, J. D., Ngeow, C. -C., Nugent, P. E., and Wozniak, P.. Tue . "iPTF Discovery of the Rapid “Turn-on” of a Luminous Quasar". United States. doi:10.3847/1538-4357/835/2/144. https://www.osti.gov/servlets/purl/1393611.
@article{osti_1393611,
title = {iPTF Discovery of the Rapid “Turn-on” of a Luminous Quasar},
author = {Gezari, S. and Hung, T. and Cenko, S. B. and Blagorodnova, N. and Yan, Lin and Kulkarni, S. R. and Mooley, K. and Kong, A. K. H. and Cantwell, T. M. and Yu, P. C. and Cao, Y. and Fremling, C. and Neill, J. D. and Ngeow, C. -C. and Nugent, P. E. and Wozniak, P.},
abstractNote = {We present a radio-quiet quasar at z = 0.237 discovered "turning on" by the intermediate Palomar Transient Factory (iPTF). The transient, iPTF 16bco, was detected by iPTF in the nucleus of a galaxy with an archival Sloan Digital Sky Survey spectrum with weak narrow-line emission characteristic of a low-ionization nuclear emission-line region (LINER). Our follow-up spectra show the dramatic appearance of broad Balmer lines and a power-law continuum characteristic of a luminous ( Lbol ≈ 1045 erg s-1) type 1 quasar 12 yr later. Our photometric monitoring with PTF from 2009-2012 and serendipitous X-ray observations from the XMM-Newton Slew Survey in 2011 and 2015 constrain the change of state to have occurred less than 500 days before the iPTF detection. An enhanced broad Hα/[O iii] λ5007 line ratio in the type 1 state relative to other changing-look quasars also is suggestive of the most rapid change of state yet observed in a quasar. Here, we argue that the > 10 increase in Eddington ratio inferred from the brightening in UV and X-ray continuum flux is more likely due to an intrinsic change in the accretion rate of a preexisting accretion disk than an external mechanism such as variable obscuration, microlensing, or the tidal disruption of a star. However, further monitoring will be helpful in better constraining the mechanism driving this change of state. The rapid "turn-on" of the quasar is much shorter than the viscous infall timescale of an accretion disk and requires a disk instability that can develop around a ~ 108 M⊙ black hole on timescales less than 1 yr.},
doi = {10.3847/1538-4357/835/2/144},
journal = {The Astrophysical Journal (Online)},
number = 2,
volume = 835,
place = {United States},
year = {Tue Jan 24 00:00:00 EST 2017},
month = {Tue Jan 24 00:00:00 EST 2017}
}

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Cited by: 11works
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  • We present the first results of a survey for high-redshift, z ≥ 6, quasars using izY multicolour photometric observations from the Dark Energy Survey (DES). Here we report the discovery and spectroscopic confirmation of the z AB, Y AB = 20.2, 20.2 (M 1450 = -26.5) quasar DES J0454-4448 with a redshift of z = 6.09±0.02 based on the onset of the Ly α forest and an H I near zone size of 4.1 +1.1 -1.2 proper Mpc. The quasar was selected as an i-band drop out with i-z = 2.46 and z AB < 21.5 from an area ofmore » ~300 deg 2. It is the brightest of our 43 candidates and was identified for spectroscopic follow-up solely based on the DES i-z and z-Y colours. The quasar is detected by WISE and has W1 AB = 19.68. The discovery of one spectroscopically confirmed quasar with 5.7 < z < 6.5 and zAB ≤ 20.2 is consistent with recent determinations of the luminosity function at z ~ 6. DES when completed will have imaged ~5000 deg 2 to Y AB = 23.0 (5σ point source) and we expect to discover 50–100 new quasars with z > 6 including 3–10 with z > 7 dramatically increasing the numbers of quasars currently known that are suitable for detailed studies.« less
  • We present the first results of a survey for high-redshift, z ≥ 6, quasars using izY multicolour photometric observations from the Dark Energy Survey (DES). Here we report the discovery and spectroscopic confirmation of the z AB, Y AB = 20.2, 20.2 (M 1450 = –26.5) quasar DES J0454–4448 with a redshift of z = 6.09±0.02 based on the onset of the Ly α forest and an H i near zone size of 4.1 +1.1 –1.2 proper Mpc. The quasar was selected as an i-band drop out with i–z = 2.46 and z AB < 21.5 from an area ofmore » ~300 deg 2. It is the brightest of our 43 candidates and was identified for spectroscopic follow-up solely based on the DES i–z and z–Y colours. The quasar is detected by WISE and has W1 AB = 19.68. The discovery of one spectroscopically confirmed quasar with 5.7 < z < 6.5 and z AB ≤ 20.2 is consistent with recent determinations of the luminosity function at z ~ 6. DES when completed will have imaged ~5000 deg 2 to Y AB = 23.0 (5σ point source) and we expect to discover 50–100 new quasars with z > 6 including 3–10 with z > 7 dramatically increasing the numbers of quasars currently known that are suitable for detailed studies.« less
  • In this report, we present the first results of a survey for high-redshift, z ≥ 6, quasars using izY multicolour photometric observations from the Dark Energy Survey (DES). Here we report the discovery and spectroscopic confirmation of the z AB, Y AB = 20.2, 20.2 (M 1450 = –26.5) quasar DES J0454–4448 with a redshift of z = 6.09±0.02 based on the onset of the Ly α forest and an H i near zone size of 4.1 +1.1 –1.2 proper Mpc. The quasar was selected as an i-band drop out with i–z = 2.46 and z AB < 21.5 frommore » an area of ~300 deg 2. It is the brightest of our 43 candidates and was identified for spectroscopic follow-up solely based on the DES i–z and z–Y colours. The quasar is detected by WISE and has W1 AB = 19.68. The discovery of one spectroscopically confirmed quasar with 5.7 < z < 6.5 and z AB ≤ 20.2 is consistent with recent determinations of the luminosity function at z ~ 6. DES when completed will have imaged ~5000 deg 2 to Y AB = 23.0 (5σ point source) and we expect to discover 50–100 new quasars with z > 6 including 3–10 with z > 7 dramatically increasing the numbers of quasars currently known that are suitable for detailed studies.« less
  • Modern wide-field, optical time-domain surveys must solve a basic optimization problem: maximize the number of transient discoveries or minimize the follow-up needed for the new discoveries. Here, we describe the Color Me Intrigued experiment, the first from the intermediate Palomar Transient Factory (iPTF) to search for transients simultaneously in themore » $$g_\mathrm{PTF}$$- and $$R_\mathrm{PTF}$$-bands. During the course of this experiment we discovered iPTF$$\,$$16fnm, a new member of the 02cx-like subclass of type Ia supernovae (SNe). iPTF$$\,$$16fnm peaked at $$M_{g_\mathrm{PTF}} = -15.09 \pm 0.17 \; \mathrm{mag}$$, making it the second least-luminous known type Ia SN. iPTF 16fnm exhibits all the hallmarks of the 02cx-like class: (i) low luminosity at peak, (ii) low ejecta velocities, and (iii) a non-nebular spectra several months after peak. Spectroscopically, iPTF$$\,$$16fnm exhibits a striking resemblence to 2 other low-luminosity 02cx-like SNe: SNe 2007qd and 2010ae. iPTF$$\,$$16fnm and SN 2005hk decline at nearly the same rate, despite a 3 mag difference in brightness at peak. When considering the full subclass of 02cx-like SNe, we do not find evidence for a tight correlation between peak luminosity and decline rate in either the $g'$ or $r'$ band. We further examine the $g' - r'$ evolution of 02cx-like SNe and find that their unique color evolution can be used to separate them from 91bg-like and normal type Ia SNe. This selection function will be especially important in the spectroscopically incomplete Zwicky Transient Facility/Large Synoptic Survey Telescope era. We measure the relative rate of 02cx-like SNe to normal SNe Ia and find $$r_{N_{02cx}/N_{Ia}} = 25^{+75}_{-18.5}\%$$. Finally, we close by recommending that LSST periodically evaluate, and possibly update, its observing cadence to maximize transient science.« less
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