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Published August 10, 2022 | Version Published + Accepted Version
Journal Article Open

SRGA J181414.6-225604: A New Galactic Symbiotic X-Ray Binary Outburst Triggered by an Intense Mass-loss Episode of a Heavily Obscured Mira Variable

Creators

  • 1. ROR icon Massachusetts Institute of Technology
  • 2. ROR icon Space Research Institute
  • 3. ROR icon University of Chinese Academy of Sciences
  • 4. ROR icon University of Sydney
  • 5. ROR icon Harvard-Smithsonian Center for Astrophysics
  • 6. ROR icon California Institute of Technology
  • 7. ROR icon UNSW Sydney
  • 8. ROR icon Space Telescope Science Institute
  • 9. ROR icon Arkansas Tech University
  • 10. ROR icon University of Arizona
  • 11. ROR icon Institute of Space and Astronautical Science
  • 12. ROR icon Australian National University
  • 13. ROR icon University of Maryland, College Park

Abstract

We present the discovery and multiwavelength characterization of SRGA J181414.6-225604, a Galactic hard X-ray transient discovered during the ongoing SRG/ART-XC sky survey. Using data from the Palomar Gattini-IR survey, we identify a spatially and temporally coincident variable infrared (IR) source, IRAS 18111-2257, and classify it as a very-late-type (M7–M8), long-period (1502 ± 24 days), and luminous (M_K ≈ −9.9 ± 0.2) O-rich Mira donor star located at a distance of ≈14.6^(+2.9)_(−2.3) kpc. Combining multicolor photometric data over the last ≈25 yr, we show that the IR counterpart underwent a recent (starting ≈800 days before the X-ray flare) enhanced mass-loss (reaching ≈2.1 × 10⁻⁵ M_⊙ yr⁻¹) episode, resulting in an expanding dust shell obscuring the underlying star. Multi-epoch follow-up observations from Swift, NICER, and NuSTAR reveal a ≈200 day long X-ray outburst reaching a peak luminosity of L_ₓ ≈ 2.5 × 10³⁶ erg s⁻¹, characterized by a heavily absorbed (N_H ≈ 6 × 10²² cm⁻²) X-ray spectrum consistent with an optically thick Comptonized plasma. The X-ray spectral and timing behavior suggest the presence of clumpy wind accretion, together with a dense ionized nebula overabundant in silicate material surrounding the compact object. Together, we show that SRGA J181414.6-225604 is a new symbiotic X-ray binary in outburst, triggered by an intense dust-formation episode of a highly evolved donor. Our results offer the first direct confirmation for the speculated connection between enhanced late-stage donor mass loss and the active lifetimes of symbiotic X-ray binaries.

Additional Information

© 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Received 2022 March 7; revised 2022 May 15; accepted 2022 May 17; published 2022 August 10. We thank the anonymous referee for a careful reading of the manuscript and for providing valuable feedback that helped to improve its contents. We thank T. Maccarone, D. Rogantini, P. Pradhan, R. Remillard, and M Guenther for valuable discussions. We thank the Swift, NICER, and NuSTAR teams for approving the Target of Opportunity observations of the transient. Support for this work was provided by NASA through the NASA Hubble Fellowship grant #HST-HF2-51477.001, awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. PGIR is generously funded by Caltech, Australian National University, the Mt Cuba Foundation, the Heising-Simons Foundation, and the Bi-national Science Foundation. PGIR is a collaborative project among Caltech, Australian National University, University of New South Wales, Columbia University, and the Weizmann Institute of Science. This work is based on data from the Mikhail Pavlinsky ART-XC X-ray telescope on board the SRG observatory. The SRG observatory was built by Roskosmos in the interests of the Russian Academy of Sciences, represented by its Space Research Institute (IKI) in the framework of the Russian Federal Space Program, with the participation of the Deutsches Zentrum für Luft und Raumfahrt (DLR). The SRG spacecraft was designed, built, launched, and is operated by the Lavochkin Association and its subcontractors. The science data are downlinked via the Deep Space Network Antennae in Bear Lakes, Ussurijsk, and Baykonur, funded by Roskosmos. The ART-XC team thank the Russian Space Agency, the Russian Academy of Sciences, and State Corporation Rosatom, for the support for the SRG project and the ART-XC telescope, and the Lavochkin Association (NPOL) and partners for the creation and operation of the SRG spacecraft (Navigator). This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile. We acknowledge the Visiting Astronomer Facility at the Infrared Telescope Facility, which is operated by the University of Hawaii under Cooperative Agreement no. NNX-08AE38A with the National Aeronautics and Space Administration, Science Mission Directorate, Planetary Astronomy Program. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawaiian community. The work of I.M., A.L., and A.S. was supported by the Russian Science Foundation grant 19-12-00423. R.S. acknowledges grant No. 12073029 from the National Science Foundation of China. C.P. acknowledges financial support from the Swiss National Science Foundation (SNF). Facilities: ROSAT, INTEGRAL, XMM Newton, SRG: ART-XC, NICER, Swift, NuSTAR, PO: 0.3 m (PGIR), PO: 1.2 m (ZTF), PO: 1.5 m (SED Machine), PO: Hale (DBSP, TripleSpec), PanSTARRS, NEOWISE, IRTF (SpeX), Magellan: Baade (FIRE), SSO: ATT (WiFeS). Software: spextool (Cushing et al. 2004), xtellcor (Vacca et al. 2003), pypeit (Prochaska et al. 2020), nustardas (V2.1), Stingray (V0.3; Bachetti et al. 2021), xspec (Arnaud 1996), emcee (Foreman-Mackey et al. 2013), DUSTY (Ivezic & Elitzur 1997), HEAsoft (v6.29c; HEASARC 2014).

Attached Files

Published - De_2022_ApJ_935_36.pdf

Accepted Version - 2205.09139.pdf

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Additional details

Identifiers

Eprint ID
114944
Resolver ID
CaltechAUTHORS:20220526-173308925

Related works

Describes
https://arxiv.org/abs/2205.09139 (URL)

Funding

NASA Hubble Fellowship
HST-HF2-51477.001
NASA
NAS5-26555
Caltech
Australian National University
Mt. Cuba Astronomical Foundation
Heising-Simons Foundation
Binational Science Foundation (USA-Israel)
Roskosmos
Russian Space Agency
Russian Academy of Sciences
RosAtom
NASA
NNX-08AE38A
Russian Science Foundation
19-12-00423
National Natural Science Foundation of China
12073029
Swiss National Science Foundation (SNSF)

Dates

Created
2022-06-01
Created from EPrint's datestamp field
Updated
2022-08-16
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Astronomy Department, NuSTAR, Space Radiation Laboratory