MITSuME observation of V404 Cygni in the 2015 outburst: Two optical variable components with different variability
arXiv:1705.06003 · doi:10.1093/pasj/psx040
Abstract
The black hole binary V404 Cygni (= GS 2023+338) had an outburst on June 15, 2015 after 26 years of quiescence. We report the multi-color optical observation (g', Rc, and Ic) of this object at the beginning of its outburst performed by the MITSuME 50cm telescope in Akeno, Yamanashi, and the MURIKABUSHI 105 cm Telescope at Ishigakijima Astronomical Observatory. With time domain analysis of the multi-color light curves, we successfully decomposed optical variations into two components: a highly-variable, and a little-variable component. The loci of the little-variable component in the color-color diagram are consistent with that of the multi-temperature blackbody radiation, while those of the highly-variable component trace out a power-law spectrum with a spectral index α~0.6-1.0. For the little-variable component, we argue that an irradiated disk with the innermost temperature higher than ~2.0 K and the outermost temperature lower than ~6.5 K is the most plausible source. The gradual rise trend of the light curve during our observation is probably due to the growing of the little-variable component. The observed spectral energy distribution (SED) from the optical to ultraviolet can be expressed by a model consisting of a power-law component and an irradiated disk component.
arXiv comment11 pages, 7 figures, 3 tables
References in corpus (29)
- The u'g'r'i'z' Standard Star Network
- The disc instability model of dwarf-novae and low-mass X-ray binary transients
- The May 1989 outburst of the Soft X-ray Transient GS 2023+338 (V404 Cyg)
- Non-linear X-ray variability in X-ray binaries and active galaxies
- GRS 1915+105 and the Disc-Jet Coupling in Accreting Black Hole Systems
- Evidence for a Disk-Jet Interaction in the Microquasar GRS 1915+105
- XMM-Newton study of the complex and variable spectrum of NGC 4051
- Near-Infrared Spectroscopy of Low Mass X-ray Binaries : Accretion Disk Contamination and Compact Object Mass Determination in V404 Cyg and Cen X-4
- Regulation of black-hole accretion by a disk wind during a violent outburst of V404 Cygni
- Revisiting a fundamental test of the disc instability model for X-ray binaries
- The nature of X-ray spectral variability in Seyfert Galaxies
- Correlated optical, X-ray, and gamma-ray flaring activity seen with INTEGRAL during the 2015 outburst of V404 Cygni
- Repetitive Patterns in Rapid Optical Variations in the Nearby Black-hole Binary V404 Cygni
- High Resolution Chandra HETG spectroscopy of V404 Cygni in Outburst
- The Quiescent Spectral Energy Distribution of V404 Cyg
- Furiously Fast and Red: Sub-second Optical Flaring in V404 Cyg during the 2015 Outburst Peak
- Magnetic flares and the optical variability of the X-ray transient XTE J1118+480
- Multicolour observations of V404 Cyg with ULTRACAM
- The formation of the black hole in the X-ray binary system V404 Cyg
- Time-resolved optical/near-IR polarimetry of V404 Cyg during its 2015 outburst
- SWIFT view of the 2015 outburst of GS 2023+338 (V404 Cyg): complex evolution of spectral and temporal characteristics
- First INTEGRAL observations of V404 Cygni during the 2015 outburst : spectral behavior in the 20 - 650 keV energy range
- X-ray spectral evolution of V404 Cygni in the initial phase of the 2015 outburst
- Suzaku Studies of the Central Engine in the Typical Type I Seyfert NGC 3227: Detection of Multiple Primary X-ray Continua with Distinct Properties
- No Evidence of Intrinsic Optical/Near-Infrared Linear Polarization for V404 Cygni During its Bright Outburst in 2015: Broadband Modeling and Constraint on Jet Parameters
- MASTER optical polarization variability detection in the Microquasar V404 Cyg/GS2023+33
- Rapid Optical Fluctuations in the Black Hole Binary, V4641 Sgr
- The nova-like nebular optical spectrum of V404 Cygni at the beginning of the 2015 outburst decay
- Multi-colour optical photometry of V404 Cygni in outburst