Optical and X-ray studies of Be/X-ray binary 1A 0535+262 during its 2020 giant outburst
arXiv:2211.09491 · doi:10.1093/mnras/stac3354
Abstract
We report results obtained from the optical and X-ray studies of the Be/X-ray binary 1A 0535+262/HD 245770 during the 2020 October giant X-ray outburst, using the 1.2 m telescope at Mount Abu Infrared observatory and AstroSat, respectively. The peak flux of the outburst was recorded to be around 11 Crab in the 15-50 keV range, the highest ever observed from the pulsar. We performed optical observations in the 6000-7200 angstroms band before, during, and after the outburst to investigate the evolution of the circumstellar disc of the Be star between 2020 February and 2022 February. Our optical spectra exhibit prominent emission lines at 6563 angstroms (H I), 6678 angstroms (He I), and 7065 angstroms (He I). We found a significantly variable Halpha line in the spectra. The single-peaked line profile appeared asymmetric with broad red- & blue-wings in the data before and during the outburst. The post-outburst observations, however, resulted in a double-peaked profile with asymmetry in the blue-wing. Our observations before the outburst confirmed a larger Be disc that decreased in size as the outburst progressed. Furthermore, the observed variabilities in the Halpha line profile and parameters suggest the presence of a highly misaligned, precessing, and warped Be disc. AstroSat observation of the pulsar detected pulsations at around 103.55 s in the light curve up to 110 keV. We found strongly energy-dependent pulse profiles with increasing contribution of the pulsing component in hard X-rays. The broadband spectral fitting in the 0.7-90.0 keV range confirmed the presence of the known cyclotron resonance scattering feature at around 46.3 keV.
arXiv comment18 pages, 13 figures, This paper has been accepted for publication in MNRAS
References in corpus (47)
- On the Absorption of X-rays in the Interstellar Medium
- Atomic Data for Astrophysics. II. New Analytic Fits for Photoionization Cross Sections of Atoms and Ions
- Estimating distances from parallaxes IV: Distances to 1.33 billion stars in Gaia Data Release 2
- Observations of Accreting Pulsars
- Be/X-ray binaries
- The Swift/BAT Hard X-ray Transient Monitor
- A natural explanation for periodic X-ray outbursts in Be/X-ray binaries
- Viscous Effects on the Interaction between the Coplanar Decretion Disc and the Neutron Star in Be/X-Ray Binaries
- The Be/X-ray transient 4U 0115+63/V635 Cas I. A consistent model
- Discovery of two new persistent Be/X-ray pulsar systems
- Patterns of variability in Be/X-ray pulsars during giant outbursts
- The Be/X-ray transient 4U 0115+63/V635 Cas: II. Outburst mechanisms
- Giant Outbursts in Be/X-ray Binaries
- The Cadmium Zinc Telluride Imager on AstroSat
- In-orbit Performance of UVIT and First Results
- Tidal Warping of Be Star Decretion Discs
- Origin of Two Types of X-Ray Outbursts in Be/X-Ray Binaries. I. Accretion Scenarios
- Long-term optical/IR variability of the Be/X-ray binary LS V +44 17/RX J0440.9+4431
- Large Area X-ray Proportional Counter (LAXPC) in Orbit Performance : Calibration, background, analysis software
- Cyclotron emission, absorption, and the two faces of X-ray pulsar A 0535+262
- The Be/X-ray transient 4U 0115+63/V635 Cassiopeiae. III. Quasi-cyclic variability
- Cyclotron resonance energies at a low X-ray luminosity: A0535+262 observed with Suzaku
- Precessing Warped Be Disk Triggering the Giant Outbursts in 2009 and 2011 in A 0535+262/V725 Tau
- X-Ray and Optical Observations of A 0535+26
- Suzaku view of Be/X-ray binary pulsar GX 304-1 during Type I X-ray outbursts
- Cyclical behaviour and disc truncation in the Be/X-ray binary A0535+26
- A 0535+26: Back in business
- Decade long RXTE monitoring observations of Be/X-ray binary pulsar EXO 2030+375
- Timing and Spectral properties of Be/X-ray pulsar EXO 2030+375 during a Type I outburst
- On the relationship between circumstellar disc size and X-ray outbursts in Be/X-ray binaries
- A double-peaked outburst of A 0535+26 observed with INTEGRAL, RXTE, and Suzaku
- Joint H-alpha and X-ray Observations of Massive X-ray Binaries. I. The B-Supergiant System LS I +65 010 = 2S 0114+650
- Broad band X-ray spectroscopy of A0535+262 with SUZAKU
- Discrete Mass Ejections from the Be/X-ray Binary A0535+26/HD245770
- Drastic Spectroscopic Variability of the Be/X-ray Binary A0535+262/V725 Tau during and after the 2009 Giant Outburst
- Disc loss and renewal in A0535+26
- H-alpha observations of the gamma-ray-emitting Be/X-ray binary LSI+61303: orbital modulation, disk truncation, and long-term variability
- Long-term pulse profile study of the Be/X-ray pulsar SAX J2103.5+4545
- Warped disks during type II outbursts in Be/X-ray binaries: evidence from optical polarimetry
- Study of timing and spectral properties of the X-ray pulsar 1A 0535+262 during the giant outburst in 2020 November-December
- Suzaku Observation of Be/X-ray Binary Pulsar EXO 2030+375
- Disc-loss episode in the Be shell optical counterpart to the high-mass X-ray binary IGR J21343+4738
- Optical and near-infrared spectroscopy of Nova V2891 Cygni: evidence for shock-induced dust formation
- RAMSES II - RAMan Search for Extragalactic Symbiotic Stars. Project concept, commissioning, and early results from the science verification phase
- Optical spectroscopy of the Be/X-ray Binary V850 Cen/GX 304-1 during faint X-ray periodical activity
- Design and Development of Mt. Abu Faint Object Spectrograph and Camera -- Pathfinder (MFOSC-P) for PRL 1.2m Mt. Abu Telescope
- High-dispersion spectroscopic monitoring of the Be/X-ray binary A0535+26/V725 Tau I: The long-term profile variability