scholarly journals C iv black hole mass measurements with the Australian Dark Energy Survey (OzDES)

2019 ◽  
Vol 487 (3) ◽  
pp. 3650-3663 ◽  
Author(s):  
J K Hoormann ◽  
P Martini ◽  
T M Davis ◽  
A King ◽  
C Lidman ◽  
...  

ABSTRACT Black hole mass measurements outside the local Universe are critically important to derive the growth of supermassive black holes over cosmic time, and to study the interplay between black hole growth and galaxy evolution. In this paper, we present two measurements of supermassive black hole masses from reverberation mapping (RM) of the broad C iv emission line. These measurements are based on multiyear photometry and spectroscopy from the Dark Energy Survey Supernova Program (DES-SN) and the Australian Dark Energy Survey (OzDES), which together constitute the OzDES RM Program. The observed reverberation lag between the DES continuum photometry and the OzDES emission line fluxes is measured to be $358^{+126}_{-123}$ and $343^{+58}_{-84}$ d for two quasars at redshifts of 1.905 and 2.593, respectively. The corresponding masses of the two supermassive black holes are 4.4 × 109 and 3.3 × 109 M⊙, which are among the highest redshift and highest mass black holes measured to date with RM studies. We use these new measurements to better determine the C iv radius−luminosity relationship for high-luminosity quasars, which is fundamental to many quasar black hole mass estimates and demographic studies.

Author(s):  
Yu-Ching Chen ◽  
Xin Liu ◽  
Wei-Ting Liao ◽  
A Miguel Holgado ◽  
Hengxiao Guo ◽  
...  

Abstract Periodically variable quasars have been suggested as close binary supermassive black holes. We present a systematic search for periodic light curves in 625 spectroscopically confirmed quasars with a median redshift of 1.8 in a 4.6 deg2 overlapping region of the Dark Energy Survey Supernova (DES-SN) fields and the Sloan Digital Sky Survey Stripe 82 (SDSS-S82). Our sample has a unique 20-year long multi-color (griz) light curve enabled by combining DES-SN Y6 observations with archival SDSS-S82 data. The deep imaging allows us to search for periodic light curves in less luminous quasars (down to r ∼23.5 mag) powered by less massive black holes (with masses ≳ 108.5M⊙) at high redshift for the first time. We find five candidates with significant (at >99.74% single-frequency significance in at least two bands with a global p-value of ∼7 × 10−4–3× 10−3 accounting for the look-elsewhere effect) periodicity with observed periods of ∼3–5 years (i.e., 1–2 years in rest frame) having ∼4–6 cycles spanned by the observations. If all five candidates are periodically variable quasars, this translates into a detection rate of ${\sim }0.8^{+0.5}_{-0.3}$% or ${\sim }1.1^{+0.7}_{-0.5}$ quasar per deg2. Our detection rate is 4–80 times larger than those found by previous searches using shallower surveys over larger areas. This discrepancy is likely caused by differences in the quasar populations probed and the survey data qualities. We discuss implications on the future direct detection of low-frequency gravitational waves. Continued photometric monitoring will further assess the robustness and characteristics of these candidate periodic quasars to determine their physical origins.


2017 ◽  
Vol 13 (S338) ◽  
pp. 61-64
Author(s):  
Robert E. Butler ◽  
M. Soares-Santos ◽  
J. Annis ◽  
K. Herner ◽  

AbstractThe DESGW program is a collaboration between members of the Dark Energy Survey, the wider astronomical community, and the LIGO-Virgo Collaboration to search for optical counterparts of gravitational wave events, such as those expected from binary neutron star mergers or neutron star-black hole mergers. While binary black hole (BBH) events are not expected to produce an electromagnetic (EM) signature, emission is certainly not impossible. The DESGW program has performed follow-up observations of four BBH events detected by LIGO in order to search for any possible EM counterpart. Failure to find such counterparts is still relevant in that it produces limits on optical emission from such events. This is a review of follow-up results from O1 BBH events and a discussion of the status of ongoing uniform re-analysis of all BBH events that DESGW has followed up to date.


2012 ◽  
Vol 8 (S295) ◽  
pp. 137-140
Author(s):  
Diego Capozzi ◽  
Daniel Thomas ◽  
Claudia Maraston ◽  
Luke J. M. Davies

AbstractThe Dark Energy Survey (DES) will be the new state-of the-art in large-scale galaxy imaging surveys. With 5,000 deg2, it will cover an area of the sky similar to SDSS-II, but will go over two magnitudes deeper, reaching 24th magnitude in all four optical bands (griz). DES will further provide observations in the redder Y-band and will be complemented with VISTA observations in the near-infrared bands JHK. Hence DES will furnish an unprecedented combination of sky and wavelength coverage and depth, unreached by any of the existing galaxy surveys. The very nature of the DES data set – large volume at intermediate photometric depth – allows us to probe galaxy formation and evolution within a cosmic-time range of ~ 10 Gyr and in different environments. In fact there will be many galaxy clusters available for galaxy evolution studies, given that one of the main aims of DES is to use their abundance to constrain the equation of state of dark energy. The X-ray follow up of these clusters, coupled with the use of gravitational lensing, will provide very precise measures of their masses, enabling us to study in detail the influence of the environment on galaxy formation and evolution processes. DES will leverage the study of these processes by allowing us to perform a detailed investigation of the galaxy luminosity and stellar mass functions and of the relationship between dark and baryonic matter as described by the Halo Occupation Distribution.


2012 ◽  
Vol 2012 ◽  
pp. 1-21 ◽  
Author(s):  
Brandon C. Kelly ◽  
Andrea Merloni

The black hole mass function of supermassive black holes describes the evolution of the distribution of black hole mass. It is one of the primary empirical tools available for mapping the growth of supermassive black holes and for constraining theoretical models of their evolution. In this paper, we discuss methods for estimating the black hole mass function, including their advantages and disadvantages. We also review the results of using these methods for estimating the mass function of both active and inactive black holes. In addition, we review current theoretical models for the growth of supermassive black holes that predict the black hole mass function. We conclude with a discussion of directions for future research which will lead to improvement in both empirical and theoretical determinations of the mass function of supermassive black holes.


2010 ◽  
Vol 6 (S277) ◽  
pp. 21-25
Author(s):  
Christopher D. Impey ◽  
Jonathan R. Trump ◽  
Jared M. Gabor ◽  

AbstractThe Cosmological Evolution Survey (COSMOS) is a unique tool for studying low level AGN activity and the co-evolution of galaxies and supermassive black holes. COSMOS involves the largest contiguous region of the sky ever imaged by HST; it includes very complete multiwavelength coverage, and the largest joint samples of galaxy and AGN redshifts in any deep survey. The result is a search for AGN with low black hole mass, low accretion rates, and levels of obscuration that can remove them from optical surveys. A complete census of intermediate mass black holes at redshifts of 1 to 3 is required to tell the story of the co-evolution of galaxies and their embedded, and episodically active, black holes.


2021 ◽  
Vol 503 (4) ◽  
pp. 6098-6111
Author(s):  
Angelo Ricarte ◽  
Michael Tremmel ◽  
Priyamvada Natarajan ◽  
Charlotte Zimmer ◽  
Thomas Quinn

ABSTRACT We characterize the population of wandering black holes, defined as those physically offset from their halo centres, in the romulus cosmological simulations. Unlike most other currently available cosmological simulations, black holes are seeded based on local gas properties and are permitted to evolve dynamically without being fixed at halo centres. Tracking these black holes allows us to make robust predictions about the offset population. We find that the number of wandering black holes scales roughly linearly with the halo mass, such that we expect thousands of wandering black holes in galaxy cluster haloes. Locally, these wanderers account for around 10 per cent of the local black hole mass budget once seed masses are accounted for. Yet for higher redshifts ($z$ ≳ 4), wandering black holes both outweigh and outshine their central supermassive counterparts. Most wandering black holes, we find, remain close to the seed mass and originate from the centres of previously disrupted satellite galaxies. While most do not retain a resolved stellar counterpart, those that do are situated farther out at larger fractions of the virial radius. Wanderers with higher luminosities are preferentially at lower radius, more massive, and either closer to their host’s mid-planes or associated with a stellar overdensity. This analysis shows that our current census of supermassive black holes is incomplete and that a substantial population of off-centre wanderers likely exists.


2006 ◽  
Vol 2 (S238) ◽  
pp. 51-58 ◽  
Author(s):  
Martin J. Rees ◽  
Marta Volonteri

AbstractSupermassive black holes are nowadays believed to reside in most local galaxies. Observations have revealed us vast information on the population of local and distant black holes, but the detailed physical properties of these dark massive objects are still to be proven. Accretion of gas and black hole mergers play a fundamental role in determining the two parameters defining a black hole: mass and spin. We briefly review here the basic properties of the population of supermassive black holes, focusing on the still mysterious formation of the first massive black holes, and their evolution from early times to now.


2010 ◽  
Vol 19 (08n10) ◽  
pp. 1233-1240 ◽  
Author(s):  
C. FILLOUX ◽  
F. DURIER ◽  
J. A. F. PACHECO ◽  
J. SILK

The correlations between the mass of supermassive black holes and the properties of their host galaxies are investigated through cosmological simulations. Black holes grow from seeds of 100 M⊙ are inserted into density peaks presented in the redshift range 12–15. Seeds grow essentially by accreting matter from a nuclear disk and also by coalescences resulting from merger episodes. At z = 0, our simulations reproduce the black hole mass function and the correlations of the black hole mass, both with stellar velocity dispersion and host dark halo mass. Moreover, the evolution of the black hole mass density derived from the present simulations agrees with that derived from the bolometric luminosity of quasars, indicating that the average accretion history of seeds is adequately reproduced. However, our simulations are unable to form black holes with masses above 109 M⊙ at z ~ 6, whose existence is inferred from the bright quasars detected by the Sloan survey in this redshift range.


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