Time-series spectroscopy of pulsating sdB stars -- III.Line indices of PG 1605+072

O'Toole, S. J.; Jørgensen, M.S.; Kjeldsen, H.; Bedding, Timothy R.; Dall, T. H.; Heber, U.

doi:10.1046/j.1365-8711.2003.06343.x

Cited by 19 publications

(21 citation statements)

References 27 publications

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“…1) as the lines are overlapping. O'Toole et al (2003b) have also found a strong dependence of line index amplitude on Balmer line order, with high order Balmer line amplitudes up to 10 times larger than H β due to the fact that the line index may not only be dependent on temperature but also on surface gravity.…”

Section: Computation Of Synthetic Line-profile Variationsmentioning

confidence: 89%

“…If the equivalent width of the given line profile is increasing with increasing temperature this absorption feature will be enhanced, whilst if the equivalent width is decreasing with increasing temperature the absorption feature will be reduced and could become an emission feature. Equivalent width variations of Balmer lines are described by a nonlinear combination of temperature and surface gravity (O'Toole et al 2003a). For hot stars such as sdBs, the change of equivalent width with temperature is negative, so that the equivalent width becomes smaller with increasing temperature and the Balmer lines are becoming shallower as the temperature is increasing and deeper as the temperature is decreasing.…”

Section: Computation Of Synthetic Line-profile Variationsmentioning

confidence: 99%

“…The first time-resolved spectroscopy study was done by Jeffery & Pollacco (2000) on PB 8783 and KPD 1929+4401, followed by extensive studies on PG 1605+072 by Woolf et al (2002), O'Toole et al (2000O'Toole et al ( , 2002O'Toole et al ( , 2003aO'Toole et al ( , 2005 and Tillich et al (2007), on PG 1325+101 by Telting & Østensen (2004), on Balloon 090100001 by Telting & Østensen (2006) and Østensen et al (2008) and most recently on PG 1219+534 by Reed et al (2009). These low-resolution spectroscopy studies were mainly focused on measuring the RV and equivalent width variations, as well as characterization of the pulsational effective temperature and gravity variations.…”

Section: Introductionmentioning

confidence: 99%

“…This is the first application of a line-profile variation study on a V361 Hya star with low photometric amplitudes (<8 mmag), no dominant frequency and a dense and narrow frequency spectrum (28 frequencies were found in a 5000 μHz range, see Table 4 of Kilkenny et al 2003). All previous time-series spectroscopy studies, including the recent line-profile analysis by Telting et al (2008), were done on V361 Hya outliers with exceptionally high amplitudes (O'Toole et al 2000(O'Toole et al , 2002(O'Toole et al , 2003a(O'Toole et al , 2005Woolf et al 2002;Telting & Østensen 2004Telting & Østensen , 2006Tillich et al 2007). …”

Section: Introductionmentioning

confidence: 99%

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Interpreting the line-profile variations of subdwarf B pulsators: the case of PG 1336-018 (NY Virginis)

Vučković¹,

Østensen²,

Aerts

et al. 2009

A&A

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Aims. We analyze the high-resolution time-resolved VLT/uves spectra of PG 1336−018, a rapidly pulsating subdwarf B (sdB) primary in a close orbit with an M5 companion, with the aim to detect the pulsational signal of the primary in line-profile variations. Methods. After removing the dominant radial-velocity component inherent to the orbital motion and taking only out-of-eclipse data we computed cross-correlation functions (CCFs) for each individual spectrum and assumed these to approximate the average line profile. We computed predictions of line-profile variations for pulsating sdB stars and present their diagnostic value for mode identification. Results. We detect the pulsation mode at 5435 μHz in the line-profile variations of the CCFs which allows us to characterize the detected pulsation mode of PG 1336−018. Conclusions. We model the pulsational perturbations of synthetic spectra for a star with physical parameters like PG 1336−018 and confront them with the observed spectra. We find that low order Balmer lines can be used as diagnostic tool to identify pulsation modes. A detailed line-profile analysis of the perturbed time-series spectra excludes the = |m| = (3, 3), (1, 0), (2, 1) and (2, 0) modes, but does not allow a unique mode identification among the radial or sectoral dipole or quadrupole modes.

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Section: Computation Of Synthetic Line-profile Variationsmentioning

confidence: 89%

Section: Computation Of Synthetic Line-profile Variationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Interpreting the line-profile variations of subdwarf B pulsators: the case of PG 1336-018 (NY Virginis)

Vučković¹,

Østensen²,

Aerts

et al. 2009

A&A

Self Cite

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“…PB 8783 and KPD 1209+4401 (Jeffery & Pollacco 2000), PG 1605+072 (O'Toole et al 2003), PG 1325+101 (Telting & Østensen 2004). Recent highresolution FUSE time-series of three sdBV were presented by Kuassivi et al (2005).…”

Section: Introductionmentioning

confidence: 99%

Time-resolved spectroscopy of the bright sdBV Balloon 090100001

Telting

Østensen

2006

A&A

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We have obtained 2552 useful low-resolution spectra of the bright sdBV Balloon 090100001, which form the first large time-resolved spectroscopic dataset of this brightest known pulsating subdwarf B star. The data were obtained at the Nordic Optical Telescope during 7 nights in August/September 2004 over a total time base of 38 nights, aiming to derive pulsational characteristics of this star. In this paper we present the observations and the results obtained from frequency analyses. In our data we find clear evidence for 8 independent frequencies, that were all previously reported in photometric monitoring studies, allowing future asteroseismological studies of this star to be constrained by combined photometric and spectroscopic observations of as much as 8 pulsation modes. We do not find conclusive evidence for new frequencies. We present the first determination of the pulsational radial-velocity amplitudes of this star, and find that the radial-velocity amplitude of the main pulsation mode ( f 1 = 2.80749 mHz) in Balloon 090100001 is 18.9 km s −1 , which is the largest radial-velocity amplitude found in sdB-star pulsations so far. For all spectra, the radial velocities are published electronically.

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Multisite spectroscopic and photometric observations of the pulsating sdB star PG 1605+072

O’Toole¹,

Falter²,

Heber³

et al. 2004

International Astronomical Union Colloquium

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We present the first results from the MultiSite Spectroscopic Telescope (MSST) observations of the sdBV star PG 1605+072. Pulsating sdB stars (V361 Hya stars) offer the chance to gain new insights into the formation and evolution of extreme Horizontal Branch stars using the tools of asteroseismology. PG 1605+072 is an outstanding object in its class, with the richest frequency spectrum, the longest periods, and the largest variations. The MSST campaign took place in 2002 May/June and we present here the massive data set, made up of 399 hr of photometry and 151 hr of spectroscopy. The overall aims of the project are to examine light/velocity amplitude ratios and phase differences, changes in equivalent width/line index, and λ-dependence of photometric amplitudes, and to use these properties for mode identification.

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Time-series spectroscopy of pulsating sdB stars -- III.Line indices of PG 1605+072

Cited by 19 publications

References 27 publications

Interpreting the line-profile variations of subdwarf B pulsators: the case of PG 1336-018 (NY Virginis)

Interpreting the line-profile variations of subdwarf B pulsators: the case of PG 1336-018 (NY Virginis)

Time-resolved spectroscopy of the bright sdBV Balloon 090100001

Multisite spectroscopic and photometric observations of the pulsating sdB star PG 1605+072

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