Revisiting multiwavelength data on the supersoft X-ray source CAL 83

Abstract

In this study we revisit public data on the supersoft X-ray source CAL 83 in the Large Magellanic Cloud. A significant part of our analysis is focused on XMM-Newton X-ray observations, in which updated data reduction procedures and quality assessment were applied. We report on the capability of publicly available hot atmosphere models in describing the source's soft X-ray spectrum. By gathering historical flux measurements in multiple wavelengths and comparing them with the fluxes derived from the X-ray analysis, we find that a $\sim$ 360 kK phenomenological blackbody model describes the spectral energy distribution of CAL 83 fairly well. We also retrieve data from the XMM-Newton UV/optical camera, which is co-alligned with the X-ray instruments and provides strictly simultaneous measurements. These observations demonstrate that the X-ray emission is definitely anti-correlated with emission at longer wavelengths in a time-scale of days to weeks. A closer look at simultaneous X-ray and UV count rates in single light curves reveals that the anti-correlated behaviour is actually present in time scales as short as minutes, suggesting that the origin of variable emission in the system is not unique.

arXiv comment9 pages, 8 figures. To be published in MNRAS

References in corpus (37)

• On the Absorption of X-rays in the Interstellar Medium
• The European Photon Imaging Camera on XMM-Newton: The MOS Cameras
• Atomic Data for Astrophysics. II. New Analytic Fits for Photoionization Cross Sections of Atoms and Ions
• A distance to the Large Magellanic Cloud that is precise to one per cent
• The XMM-Newton Optical/UV Monitor Telescope
• An Extended Grid of Nova Models: II. The Parameter Space of Nova Outbursts
• A UBVR CCD Survey of the Magellanic Clouds
• The Element Abundances in Bare Planetary Nebula Central Stars and the Shell Burning in AGB Stars
• Thermal Stability of White Dwarfs Accreting Hydrogen-rich Matter and Progenitors of Type Ia Supernovae
• Hydrogen Burning on Accreting White Dwarfs: Stability, Recurrent Novae, and the Post-Novae Supersoft Source
• A grid of synthetic ionizing spectra for very hot compact stars from NLTE model atmospheres
• A Universal Decline Law of Classical Novae
• Thermal Timescale Mass Transfer and the Evolution of White Dwarf Binaries
• Probing X-ray Absorption and Optical Extinction in the Interstellar Medium Using Chandra Observations of Supernova Remnants
• The XMM-Newton serendipitous ultraviolet source survey catalogue
• Catalog of supersoft X-ray sources
• Luminous Supersoft X-Ray Sources in External Galaxies
• The nature of the supersoft X-ray source RX~J0513--69
• NLTE model atmospheres for the hottest white dwarfs: Spectral analysis of the compact component in nova V4743 Sgr
• RX J0513.9-6951: The first example of accretion wind evolution, a key evolutionary process to Type Ia supernovae
• NLTE Model Atmosphere Analysis of the LMC Supersoft X-ray Source CAL 83
• A new super-soft X-ray source in the Small Magellanic Cloud: Discovery of the first Be/white dwarf system in the SMC?
• The spectral evolution and ejecta of recurrent nova U Sco in the 2010 outburst
• X-Ray Off States and Optical Variability in CAL 83
• NICER monitoring of supersoft X-ray sources
• Optical and X-ray Properties of CAL 83: I. Quasi-periodic Optical and Supersoft Variability
• The supersoft X-ray transient ASASSN-16oh as a thermonuclear runaway without mass ejection
• What we learn from the X-ray grating spectra of Nova SMC 2016
• XMM Spectroscopy of the Transient Supersoft Source RX J0513.9-6951: probing the dynamic white dwarf photosphere
• The X-ray off-state of the supersoft source CAL 83 and its interpretation
• Populations of super-soft X-ray sources in galaxies of different morphological types
• X-ray Pulsations in the Supersoft X-ray Binary CAL 83
• Deep XMM-Newton survey of M33
• A Revised Ephemeris and FUSE Observations of the Supersoft X-ray Source CAL 83
• An eLIMA model for the 67 s X-ray periodicity in CAL 83
• Recent discoveries of supersoft X-ray sources in M 31
• A BeppoSAX LECS observation of the super-soft source CAL83

Cited by in corpus (1)

• Application of hydrostatic local thermodynamic equilibrium atmosphere models to interpretations of supersoft X-ray source spectra