New insights on the recoiling/binary black hole candidate J0927+2943 via molecular gas observations

PG1302-102 is thought to be a supermassive binary black hole (BBH) system according to the periodical variations of its optical and UV photometry, which may be interpreted as being due to the relativistic Doppler boosting of the emission mainly from the disk around the secondary black hole (BH) modulated by its orbital motion. In this paper, we investigate several broad emission lines of PG1302-102 using archived UV spectra obtained by IUE, GALEX, and Hubble, to reveal the broad-line region (BLR) emission properties of this BBH system under the Doppler boosting scenario. We find that the broad lines Lyα, N V, C IV, and C III] all show Gaussian profiles, and none of these lines exhibits obvious periodical variation. Adopting a simple model for the BLR, we perform Markov chain Monte Carlo fittings to these broad lines, and find that the BLR must be viewed at an orientation angle of ∼33°, close to face-on. If the Doppler boosting interpretation is correct, then the BLR is misaligned with the BBH orbital plane by an angle of ∼51°, which suggests that the Doppler boosted continuum variation has little effect on the broad-line emission and thus does not lead to periodical line variation. We further discuss the possible implications for such a BLR configuration with respect to the BBH orbital plane.

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VLBA 24 and 43 GHz observations of massive binary black hole candidate PKS 1155 + 251

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stx1743 ◽

2017 ◽

Vol 471 (2) ◽

pp. 1873-1878 ◽

Cited By ~ 1

Author(s):

Xiaolong Yang ◽

Xiang Liu ◽

Jun Yang ◽

Ligong Mi ◽

Lang Cui ◽

...

Keyword(s):

Black Hole ◽

Black Hole Candidate ◽

Binary Black Hole

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A black hole X-ray binary at ∼100 Hz: multiwavelength timing of MAXI J1820+070 with HiPERCAM and NICER

Monthly Notices of the Royal Astronomical Society Letters ◽

10.1093/mnrasl/slz148 ◽

2019 ◽

Vol 490 (1) ◽

pp. L62-L66 ◽

Cited By ~ 4

Author(s):

J A Paice ◽

P Gandhi ◽

T Shahbaz ◽

P Uttley ◽

Z Arzoumanian ◽

...

Keyword(s):

Black Hole ◽

Time Scales ◽

X Rays ◽

X Ray ◽

Black Hole Candidate ◽

Optical Wavelength ◽

The Third ◽

Binary Black Hole ◽

Internal Shock ◽

Low Mass

ABSTRACT We report on simultaneous sub-second optical and X-ray timing observations of the low-mass X-ray binary black hole candidate MAXI J1820+070. The bright 2018 outburst rise allowed simultaneous photometry in five optical bands (ugrizs) with HiPERCAM/GTC (Optical) at frame rates over 100 Hz, together with NICER/ISS observations (X-rays). Intense (factor of 2) red flaring activity in the optical is seen over a broad range of time-scales down to ∼10 ms. Cross-correlating the bands reveals a prominent anticorrelation on time-scales of ∼seconds, and a narrow sub-second correlation at a lag of ≈ +165 ms (optical lagging X-rays). This lag increases with optical wavelength, and is approximately constant over Fourier frequencies of ∼0.3–10 Hz. These features are consistent with an origin in the inner accretion flow and jet base within ∼5000 Gravitational radii. An additional ∼+5 s lag feature may be ascribable to disc reprocessing. MAXI J1820+070 is the third black hole transient to display a clear ∼0.1 s optical lag, which may be common feature in such objects. The sub-second lag variation with wavelength is novel, and may allow constraints on internal shock jet stratification models.

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Confirmed short periodic variability of subparsec supermassive binary black hole candidate Mrk 231

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa737 ◽

2020 ◽

Vol 494 (3) ◽

pp. 4069-4076 ◽

Cited By ~ 3

Author(s):

Andjelka B Kovačević ◽

Tignfeng Yi ◽

Xinyu Dai ◽

Xing Yang ◽

Iva Čvorović-Hajdinjak ◽

...

Keyword(s):

Black Hole ◽

Equal Mass ◽

Optical Data ◽

Mass Ratio ◽

Data Set ◽

Black Hole Candidate ◽

Limited Sampling ◽

Binary Black Hole ◽

Low Mass ◽

Significant Periodicity

ABSTRACT Here we confirm the short periodic variability of a subparsec supermassive binary black hole (SMBBH) candidate Mrk 231 in the extended optical photometric data set collected by the Catalina Real-Time Transient Survey (CRTS) and All-Sky Automated Survey for Supernovae (ASAS-SN). Using the Lomb–Scargle periodogram and 2DHybrid method, we detected the significant periodicity of ∼1.1 yr beyond a damped random walk model in the CRTS+ASAS-SN optical data set. Mrk 231 has been previously proposed as an SMBBH candidate with a highly unequal mass ratio (q ∼ 0.03), very tight mutual separation of ∼590 au, and an orbital period of ∼1.2 yr. Hence, our result further supports, even though not prove, the intriguing hypothesis that SMBBHs with low mass ratios may be more common than close-equal mass SMBBHs. This result, however, was obtained from the contribution of the CRTS data with limited sampling cadence and photometric accuracy, and further monitoring of Mrk 231 is crucial to confirm the periodicity.

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