The Astrophysics of Emission-Line Stars

Kogure, T.; Leung, K. C.

doi:10.1007/978-0-387-68995-1

Cited by 47 publications

(38 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The quantity I = I ( v 0 / v ∞ , β) in represents the integral over the ratio between the dilution factor and the square of the velocity law v ( r ). In the case where the velocity law corresponds to a β‐law proposed by Castor & Lamers (1979) and the dilution factor is the standard formula given by Kogure & Leung (2007), the integral is given by where x = R / r , r being the distance from the centre of the source and u = v 0 / v ∞ . The speed v 0 is the initial velocity of the wind at r = R .…”

Section: Discussionmentioning

confidence: 99%

“…The quantity I = I (v 0 /v ∞ , β) in equation (1) represents the integral over the ratio between the dilution factor and the square of the velocity law v(r). In the case where the velocity law corresponds to a β-law proposed by Castor & Lamers (1979) and the dilution factor is the standard formula given by Kogure & Leung (2007), the integral is given by…”

Section: Mass Loss Via Line-driven Windsmentioning

confidence: 99%

See 1 more Smart Citation

Inflow and outflow from the accretion disc of the microquasar SS 433: UKIRT spectroscopy

Perez

Blundell

2009

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

A succession of near-IR spectroscopic observations, taken nightly throughout an entire cycle of SS 433's orbit, reveal (i) the persistent signature of SS 433's accretion disc, having a rotation speed of ∼ 500 km s −1 (ii) the presence of the circumbinary disc recently discovered at optical wavelengths by Blundell, Bowler & Schmidtobreick (2008) and (iii) a much faster outflow than has previously been measured for the disc wind. From these, we find a much faster accretion disc wind than has noted before, with a terminal velocity of ∼1500 km s −1 . The increased wind terminal velocity results in a mass-loss rate of ∼10 −4 M ⊙ yr −1 . These, together with the newly (upwardly) determined masses for the components of the SS 433 system, result in an accurate diagnosis of the extent to which SS 433 has super-Eddington flows. Our observations imply that the size of the companion star is comparable with the semi-minor axis of the orbit which is given by √ 1 − e 2 40 R ⊙ , where e is the eccentricity. Our relatively high spectral resolution at these near-IR wavelengths has enabled us to deconstruct the different components that comprise the Brackett-γ line in this binary system, and their physical origins. With this line dominated throughout our series of observations by the disc wind, and the accretion disc itself being only a minority (∼15 per cent) contribution, we caution against use of the unresolved Brackett-γ line intensity as an "accretion signature" in X-ray binaries or microquasars in any quantitative way.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Mass Loss Via Line-driven Windsmentioning

confidence: 99%

Inflow and outflow from the accretion disc of the microquasar SS 433: UKIRT spectroscopy

Perez

Blundell

2009

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

show abstract

“…These forbidden transitions are typically associated with T Tauri stars, and are an indication of accretion. The two emission lines ∼7300Å are most likely [O ii] lines(Kogure & Leung 2010). The dotted box represents the area of the inset plot.…”

mentioning

confidence: 99%

WARM DUST AROUND COOL STARS: FIELD M DWARFS WITHWISE12 OR 22 μm EXCESS EMISSION

Theissen

West

2014

ApJ

View full text Add to dashboard Cite

Using the SDSS DR7 spectroscopic catalog, we searched the WISE AllWISE catalog to investigate the occurrence of warm dust, as inferred from IR excesses, around field M dwarfs (dMs). We developed SDSS/WISE color selection criteria to identify 175 dMs (from 70,841) that show IR flux greater than typical dM photosphere levels at 12 and/or 22 µm, including seven new stars within the Orion OB1 footprint. We characterize the dust populations inferred from each IR excess, and investigate the possibility that these excesses could arise from ultracool binary companions by modeling combined SEDs. Our observed IR fluxes are greater than levels expected from ultracool companions (> 3σ). We also estimate that the probability the observed IR excesses are due to chance alignments with extragalactic sources is < 0.1%. Using SDSS spectra we measure surface gravity dependent features (K, Na, and CaH 3), and find < 15% of our sample indicate low surface gravities. Examining tracers of youth (Hα, UV fluxes, and Li absorption), we find < 3% of our sample appear young, indicating we are observing a population of field stars 1 Gyr, likely harboring circumstellar material. We investigate age-dependent properties probed by this sample, studying the disk fraction as a function of Galactic height. The fraction remains small and constant to |Z| ∼ 700 pc, and then drops, indicating little to no trend with age. Possible explanations for disks around field dMs include: 1) collisions of planetary bodies, 2) tidal disruption of planetary bodies, or 3) failed planet formation.

show abstract

“…They are expected to exhibit high intrinsic absorption mainly due to X-ray absorption by stellar wind. Companion stars of these obscured sgHMXB could evolve as follows (Kogure & Leung 2007)…”

mentioning

confidence: 99%

Infrared identification of high-mass X-ray binaries discovered by INTEGRAL

Coleiro

Chaty

Heras

et al. 2013

A&A

View full text Add to dashboard Cite

Context. Since it started observing the sky, the INTEGRAL satellite has discovered new categories of high mass X-ray binaries (HMXB) in our Galaxy. These observations raise important questions on the formation and evolution of these rare and short-lived objects. Aims. We present here new infrared observations from which to reveal or constrain the nature of 15 INTEGRAL sources, which allow us to update and discuss the Galactic HMXB population statistics. Methods. After previous photometric and spectroscopic observing campaigns in the optical and near-infrared, new photometry and spectroscopy was performed in the near-infrared with the SofI instrument on the ESO/NTT telescope in 2008 and 2010 on a sample of INTEGRAL sources. These observations, and specifically the detection of certain features in the spectra, allow the identification of these high-energy objects by comparison with published NIR spectral atlases of O and B stars.Results. We present photometric data of nine sources (IGR J10101-5654, IGR J11187-5438, IGR J11435-6109, IGR J14331-6112, IGR J16328-4726, IGR J17200-3116, IGR J17354-3255, IGR J17404-3655, and IGR J17586-2129) and spectroscopic observations of 13 sources (IGR J10101-5654, IGR J11435-6109, IGR J13020-6359, IGR J14331-6112, IGR J14488-5942, IGR J16195-4945, IGR J16318-4848, IGR J16320-4751, IGR J16328-4726, IGR J16418-4532, IGR J17354-3255, IGR J17404-3655, and IGR J17586-2129). Our spectroscopic measurements indicate that: five of these objects are Oe/Be high-mass X-ray binaries (BeHMXB), six are supergiant high-mass X-ray binaries (sgHMXB), and two are sgB [e]. From a statistical point of view, we estimate the proportion of confirmed sgHMXB to be 42% and that of the confirmed BeHMXB to be 49%. The remaining 9% are peculiar HMXB.

show abstract

The Astrophysics of Emission-Line Stars

Cited by 47 publications

References 0 publications

Inflow and outflow from the accretion disc of the microquasar SS 433: UKIRT spectroscopy

Inflow and outflow from the accretion disc of the microquasar SS 433: UKIRT spectroscopy

WARM DUST AROUND COOL STARS: FIELD M DWARFS WITHWISE12 OR 22 μm EXCESS EMISSION

Infrared identification of high-mass X-ray binaries discovered by INTEGRAL

Contact Info

Product

Resources

About