A New Class of Large-amplitude Radial-mode Hot Subdwarf Pulsators

Thomas Kupfer; Evan B. Bauer; Kevin B. Burdge; Eric C. Bellm; Lars Bildsten; Jim Fuller; J. J. Hermes; Shrinivas R. Kulkarni; Thomas A. Prince; Jan Van Roestel; Richard Dekany; Dmitry A. Duev; Michael Feeney; Matteo Giomi; Matthew J. Graham; Stephen Kaye; Russ R. Laher; Frank J. Masci; Michael Porter; Reed Riddle; David L. Shupe; Roger M. Smith; Maayane T. Soumagnac; Paula Szkody; Charlotte Ward

doi:10.3847/2041-8213/ab263c

A New Class of Large-amplitude Radial-mode Hot Subdwarf Pulsators

Thomas Kupfer, Evan B. Bauer, Kevin B. Burdge, Eric C. Bellm, Lars Bildsten, Jim Fuller, J. J. Hermes, Shrinivas R. Kulkarni, Thomas A. Prince, Jan Van Roestel, Richard Dekany, Dmitry A. Duev, Michael Feeney, Matteo Giomi, Matthew J. Graham, Stephen Kaye, Russ R. Laher, Frank J. Masci, Michael Porter, Reed RiddleDavid L. Shupe, Roger M. Smith, Maayane T. Soumagnac, Paula Szkody, Charlotte Ward

Department of Particle Physics and Astrophysics

Weizmann Institute of Science

Research output: Contribution to journal › Article › peer-review

Abstract

Using high-cadence observations from the Zwicky Transient Facility at low Galactic latitudes, we have discovered a new class of pulsating, hot compact stars. We have found four candidates, exhibiting blue colors (g - r ≤ -0.1 mag), pulsation amplitudes of >5%, and pulsation periods of 200-475 s. Fourier transforms of the light curves show only one dominant frequency. Phase-resolved spectroscopy for three objects reveals significant radial velocity, T _eff, and variations over the pulsation cycle, which are consistent with large-amplitude radial oscillations. The mean T _eff and for these stars are consistent with hot subdwarf B (sdB) effective temperatures and surface gravities. We calculate evolutionary tracks using MESA and adiabatic pulsations using GYRE for low-mass, helium-core pre-white dwarfs (pre-WDs) and low-mass helium-burning stars. Comparison of low-order radial oscillation mode periods with the observed pulsation periods show better agreement with the pre-WD models. Therefore, we suggest that these new pulsators and blue large-amplitude pulsators (BLAPs) could be members of the same class of pulsators, composed of young ≈0.25-0.35 M _o helium-core pre-WDs.

Original language	English
Article number	L35
Number of pages	6
Journal	Astrophysical Journal Letters
Volume	878
Issue number	2
DOIs	https://doi.org/10.3847/2041-8213/ab263c
State	Published - 20 Jun 2019

Keywords

asteroseismology
stars: oscillations
stars: variables: general
white dwarfs

All Science Journal Classification (ASJC) codes

Astronomy and Astrophysics
Space and Planetary Science

Access to Document

10.3847/2041-8213/ab263c

https://arxiv.org/abs/1906.00979License: Other

Cite this

Kupfer, T., Bauer, E. B., Burdge, K. B., Bellm, E. C., Bildsten, L., Fuller, J., Hermes, J. J., Kulkarni, S. R., Prince, T. A., Van Roestel, J., Dekany, R., Duev, D. A., Feeney, M., Giomi, M., Graham, M. J., Kaye, S., Laher, R. R., Masci, F. J., Porter, M., ... Ward, C. (2019). A New Class of Large-amplitude Radial-mode Hot Subdwarf Pulsators. Astrophysical Journal Letters, 878(2), Article L35. https://doi.org/10.3847/2041-8213/ab263c

@article{35520fb56f324a27bd5f5c8c8b9836f6,

title = "A New Class of Large-amplitude Radial-mode Hot Subdwarf Pulsators",

abstract = "Using high-cadence observations from the Zwicky Transient Facility at low Galactic latitudes, we have discovered a new class of pulsating, hot compact stars. We have found four candidates, exhibiting blue colors (g - r ≤ -0.1 mag), pulsation amplitudes of >5%, and pulsation periods of 200-475 s. Fourier transforms of the light curves show only one dominant frequency. Phase-resolved spectroscopy for three objects reveals significant radial velocity, T eff, and variations over the pulsation cycle, which are consistent with large-amplitude radial oscillations. The mean T eff and for these stars are consistent with hot subdwarf B (sdB) effective temperatures and surface gravities. We calculate evolutionary tracks using MESA and adiabatic pulsations using GYRE for low-mass, helium-core pre-white dwarfs (pre-WDs) and low-mass helium-burning stars. Comparison of low-order radial oscillation mode periods with the observed pulsation periods show better agreement with the pre-WD models. Therefore, we suggest that these new pulsators and blue large-amplitude pulsators (BLAPs) could be members of the same class of pulsators, composed of young ≈0.25-0.35 M o helium-core pre-WDs.",

keywords = "asteroseismology, stars: oscillations, stars: variables: general, white dwarfs",

author = "Thomas Kupfer and Bauer, {Evan B.} and Burdge, {Kevin B.} and Bellm, {Eric C.} and Lars Bildsten and Jim Fuller and Hermes, {J. J.} and Kulkarni, {Shrinivas R.} and Prince, {Thomas A.} and {Van Roestel}, Jan and Richard Dekany and Duev, {Dmitry A.} and Michael Feeney and Matteo Giomi and Graham, {Matthew J.} and Stephen Kaye and Laher, {Russ R.} and Masci, {Frank J.} and Michael Porter and Reed Riddle and Shupe, {David L.} and Smith, {Roger M.} and Soumagnac, {Maayane T.} and Paula Szkody and Charlotte Ward",

year = "2019",

month = jun,

day = "20",

doi = "10.3847/2041-8213/ab263c",

language = "الإنجليزيّة",

volume = "878",

journal = "Astrophysical Journal Letters",

issn = "2041-8205",

publisher = "American Astronomical Society",

number = "2",

}

Kupfer, T, Bauer, EB, Burdge, KB, Bellm, EC, Bildsten, L, Fuller, J, Hermes, JJ, Kulkarni, SR, Prince, TA, Van Roestel, J, Dekany, R, Duev, DA, Feeney, M, Giomi, M, Graham, MJ, Kaye, S, Laher, RR, Masci, FJ, Porter, M, Riddle, R, Shupe, DL, Smith, RM, Soumagnac, MT, Szkody, P & Ward, C 2019, 'A New Class of Large-amplitude Radial-mode Hot Subdwarf Pulsators', Astrophysical Journal Letters, vol. 878, no. 2, L35. https://doi.org/10.3847/2041-8213/ab263c

TY - JOUR

T1 - A New Class of Large-amplitude Radial-mode Hot Subdwarf Pulsators

AU - Kupfer, Thomas

AU - Bauer, Evan B.

AU - Burdge, Kevin B.

AU - Bellm, Eric C.

AU - Bildsten, Lars

AU - Fuller, Jim

AU - Hermes, J. J.

AU - Kulkarni, Shrinivas R.

AU - Prince, Thomas A.

AU - Van Roestel, Jan

AU - Dekany, Richard

AU - Duev, Dmitry A.

AU - Feeney, Michael

AU - Giomi, Matteo

AU - Graham, Matthew J.

AU - Kaye, Stephen

AU - Laher, Russ R.

AU - Masci, Frank J.

AU - Porter, Michael

AU - Riddle, Reed

AU - Shupe, David L.

AU - Smith, Roger M.

AU - Soumagnac, Maayane T.

AU - Szkody, Paula

AU - Ward, Charlotte

PY - 2019/6/20

Y1 - 2019/6/20

N2 - Using high-cadence observations from the Zwicky Transient Facility at low Galactic latitudes, we have discovered a new class of pulsating, hot compact stars. We have found four candidates, exhibiting blue colors (g - r ≤ -0.1 mag), pulsation amplitudes of >5%, and pulsation periods of 200-475 s. Fourier transforms of the light curves show only one dominant frequency. Phase-resolved spectroscopy for three objects reveals significant radial velocity, T eff, and variations over the pulsation cycle, which are consistent with large-amplitude radial oscillations. The mean T eff and for these stars are consistent with hot subdwarf B (sdB) effective temperatures and surface gravities. We calculate evolutionary tracks using MESA and adiabatic pulsations using GYRE for low-mass, helium-core pre-white dwarfs (pre-WDs) and low-mass helium-burning stars. Comparison of low-order radial oscillation mode periods with the observed pulsation periods show better agreement with the pre-WD models. Therefore, we suggest that these new pulsators and blue large-amplitude pulsators (BLAPs) could be members of the same class of pulsators, composed of young ≈0.25-0.35 M o helium-core pre-WDs.

AB - Using high-cadence observations from the Zwicky Transient Facility at low Galactic latitudes, we have discovered a new class of pulsating, hot compact stars. We have found four candidates, exhibiting blue colors (g - r ≤ -0.1 mag), pulsation amplitudes of >5%, and pulsation periods of 200-475 s. Fourier transforms of the light curves show only one dominant frequency. Phase-resolved spectroscopy for three objects reveals significant radial velocity, T eff, and variations over the pulsation cycle, which are consistent with large-amplitude radial oscillations. The mean T eff and for these stars are consistent with hot subdwarf B (sdB) effective temperatures and surface gravities. We calculate evolutionary tracks using MESA and adiabatic pulsations using GYRE for low-mass, helium-core pre-white dwarfs (pre-WDs) and low-mass helium-burning stars. Comparison of low-order radial oscillation mode periods with the observed pulsation periods show better agreement with the pre-WD models. Therefore, we suggest that these new pulsators and blue large-amplitude pulsators (BLAPs) could be members of the same class of pulsators, composed of young ≈0.25-0.35 M o helium-core pre-WDs.

KW - asteroseismology

KW - stars: oscillations

KW - stars: variables: general

KW - white dwarfs

UR - http://www.scopus.com/inward/record.url?scp=85069435527&partnerID=8YFLogxK

U2 - 10.3847/2041-8213/ab263c

DO - 10.3847/2041-8213/ab263c

M3 - مقالة

SN - 2041-8205

VL - 878

JO - Astrophysical Journal Letters

JF - Astrophysical Journal Letters

IS - 2

M1 - L35

ER -

A New Class of Large-amplitude Radial-mode Hot Subdwarf Pulsators

Abstract

Keywords

All Science Journal Classification (ASJC) codes

Access to Document

Other files and links

Fingerprint

Cite this