TY - JOUR
T1 - Gas phase SiO in the circumstellar environment of the recurrent nova T Coronae Borealis
AU - Evans, A.
AU - Pavlenko, Ya V.
AU - Banerjee, D. P.K.
AU - Munari, U.
AU - Gehrz, R. D.
AU - Woodward, C. E.
AU - Starrfield, S.
AU - Helton, L. A.
AU - Shahbandeh, M.
AU - Davis, S.
AU - Dallaporta, S.
AU - Cherini, G.
N1 - Publisher Copyright:
© 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.
PY - 2019/7/1
Y1 - 2019/7/1
N2 - We report the discovery of the diatomic molecule SiO in the gas phase in the environment of the recurrent nova T Coronae Borealis. While some of the SiO is photospheric, a substantial portion must arise in the wind from the red giant component of T CrB. A simple fit to the SiO feature, assuming local thermodynamic equilibrium, suggests a SiO column density of 2.8 × 1017 cm-2 and temperature ∼1000 K; the SiO column density is similar to that present in the winds of field red giants. A search for SiO maser emission is encouraged both before and after the next anticipated eruption. We find that the 12C/13C ratio in the red giant is <9, with a best-fitting value of ∼5, a factor ∼18 times lower than the solar value of 89. We find no convincing evidence for the presence of dust in the environment of T CrB, which we attribute to the destructive effects on nucleation sites of hard X-ray emission. When the next eruption of T CrB occurs, the ejected material will shock the wind, producing X-ray and coronal line emission, as is the case for the recurrent nova RS Oph. T CrB is also a good candidate for very high energy γ-ray emission, as first observed during the 2010 outburst of V407 Cyg. We include in the paper a wide variety of infrared spectroscopic and photometric data.
AB - We report the discovery of the diatomic molecule SiO in the gas phase in the environment of the recurrent nova T Coronae Borealis. While some of the SiO is photospheric, a substantial portion must arise in the wind from the red giant component of T CrB. A simple fit to the SiO feature, assuming local thermodynamic equilibrium, suggests a SiO column density of 2.8 × 1017 cm-2 and temperature ∼1000 K; the SiO column density is similar to that present in the winds of field red giants. A search for SiO maser emission is encouraged both before and after the next anticipated eruption. We find that the 12C/13C ratio in the red giant is <9, with a best-fitting value of ∼5, a factor ∼18 times lower than the solar value of 89. We find no convincing evidence for the presence of dust in the environment of T CrB, which we attribute to the destructive effects on nucleation sites of hard X-ray emission. When the next eruption of T CrB occurs, the ejected material will shock the wind, producing X-ray and coronal line emission, as is the case for the recurrent nova RS Oph. T CrB is also a good candidate for very high energy γ-ray emission, as first observed during the 2010 outburst of V407 Cyg. We include in the paper a wide variety of infrared spectroscopic and photometric data.
KW - circumstellar matter
KW - infrared: stars
KW - novae, cataclysmic variables
KW - stars: AGB and post-AGB
KW - stars: individual: T CrB
UR - http://www.scopus.com/inward/record.url?scp=85072273347&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85072273347&partnerID=8YFLogxK
U2 - 10.1093/mnras/stz1071
DO - 10.1093/mnras/stz1071
M3 - Article
AN - SCOPUS:85072273347
SN - 0035-8711
VL - 486
SP - 3498
EP - 3505
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 3
ER -