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Faint Rapid Red Transients from Neutron Star - CO White Dwarf Mergers

Zenati, Yossef ; Bobrick, Alexey LU orcid and Perets, Hagai (2020) In Monthly Notices of the Royal Astronomical Society 493(3). p.3956-3965
Abstract
Mergers of neutron stars (NS) and white dwarfs (WD) may give rise to observable explosive transientevents. We use 3D hydrodynamical (SPH) simulations, as well as 2D hydrodynamical-thermonuclearsimulations (using the FLASH AMR code) to model the disruption of CO-WDs by NSs, whichproduce faint transient events. We post-process the simulations using a large nuclear network andmake use of the SuperNu radiation-transfer code to predict the observational signatures and detailedproperties of these transients. We calculate the light-curves (LC) and spectra for five models of NS -CO-WD mergers. The small yields of56Ni (few×10−3M) result in faint, rapidly-evolving reddenedtransients (RRTs) with B (R) - peak magnitudes of at most∼−12... (More)
Mergers of neutron stars (NS) and white dwarfs (WD) may give rise to observable explosive transientevents. We use 3D hydrodynamical (SPH) simulations, as well as 2D hydrodynamical-thermonuclearsimulations (using the FLASH AMR code) to model the disruption of CO-WDs by NSs, whichproduce faint transient events. We post-process the simulations using a large nuclear network andmake use of the SuperNu radiation-transfer code to predict the observational signatures and detailedproperties of these transients. We calculate the light-curves (LC) and spectra for five models of NS -CO-WD mergers. The small yields of56Ni (few×10−3M) result in faint, rapidly-evolving reddenedtransients (RRTs) with B (R) - peak magnitudes of at most∼−12 (−13) to∼−13 (−15), muchshorter and fainter than both regular and faint/peculiar type-Ia SNe. These transients are likely to beaccompanied by several months-long, 1–2 mag dimmer red/IR afterglows. We show that the spectraof RRTs share some similarities with rapidly-evolving transients such as SN2010x, although RRTsare significantly fainter, especially in the I/R bands, and show far stronger Si lines. We estimate thatthe upcoming Large Synoptic Survey Telescope could detect RRTs at a rate of up to∼10−70 yr−1,through observations in the R/I bands. The qualitative agreement between the SPH and FLASHapproaches supports the earlier hydrodynamical studies of these systems. (Less)
Please use this url to cite or link to this publication:
author
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organization
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type
Contribution to journal
publication status
published
subject
in
Monthly Notices of the Royal Astronomical Society
volume
493
issue
3
pages
10 pages
publisher
Oxford University Press
external identifiers
  • scopus:85084753244
ISSN
1365-2966
DOI
10.1093/mnras/staa507
language
English
LU publication?
yes
id
01b97715-5e4c-4997-a36d-cb4311d3609d
alternative location
https://ui.adsabs.harvard.edu/abs/2020MNRAS.tmp..475Z/abstract
date added to LUP
2020-03-02 13:47:20
date last changed
2024-04-03 02:29:50
@article{01b97715-5e4c-4997-a36d-cb4311d3609d,
  abstract     = {{Mergers of neutron stars (NS) and white dwarfs (WD) may give rise to observable explosive transientevents. We use 3D hydrodynamical (SPH) simulations, as well as 2D hydrodynamical-thermonuclearsimulations  (using  the  FLASH  AMR  code)  to  model  the  disruption  of  CO-WDs  by  NSs,  whichproduce faint transient events. We post-process the simulations using a large nuclear network andmake use of the SuperNu radiation-transfer code to predict the observational signatures and detailedproperties of these transients. We calculate the light-curves (LC) and spectra for five models of NS -CO-WD mergers. The small yields of56Ni (few×10−3M) result in faint, rapidly-evolving reddenedtransients (RRTs) with B (R) - peak magnitudes of at most∼−12 (−13) to∼−13 (−15), muchshorter and fainter than both regular and faint/peculiar type-Ia SNe. These transients are likely to beaccompanied by several months-long, 1–2 mag dimmer red/IR afterglows. We show that the spectraof RRTs share some similarities with rapidly-evolving transients such as SN2010x, although RRTsare significantly fainter, especially in the I/R bands, and show far stronger Si lines. We estimate thatthe upcoming Large Synoptic Survey Telescope could detect RRTs at a rate of up to∼10−70 yr−1,through observations in the R/I bands. The qualitative agreement between the SPH and FLASHapproaches supports the earlier hydrodynamical studies of these systems.}},
  author       = {{Zenati, Yossef and Bobrick, Alexey and Perets, Hagai}},
  issn         = {{1365-2966}},
  language     = {{eng}},
  number       = {{3}},
  pages        = {{3956--3965}},
  publisher    = {{Oxford University Press}},
  series       = {{Monthly Notices of the Royal Astronomical Society}},
  title        = {{Faint Rapid Red Transients from Neutron Star - CO White Dwarf Mergers}},
  url          = {{http://dx.doi.org/10.1093/mnras/staa507}},
  doi          = {{10.1093/mnras/staa507}},
  volume       = {{493}},
  year         = {{2020}},
}