MK spectral types for OB(+) stars in the southern Milky Way

Vijapurkar, Jyotsna; Drilling, J. S.

doi:10.1086/191849

Cited by 57 publications

(42 citation statements)

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“…Its presence and its EW are often found in early B supergiants (e.g., Leitherer 1988). Besides this, and following the spectral type classification criteria of Jaschek & Jaschek (1987), the narrowness of the other detected Balmer lines in absorption, the absence of He ii lines, and the presence of He i and light metal (such as C iii) absorption lines suggest that the star is an early B-type supergiant, in agreement with the B1 Ia classification of Vijapurkar & Drilling (1993). Although this is not sufficient to firmly identify HD 306414 as a HMXB optical counterpart of IGR J11215−5952, it is intriguing that this hard X-ray transient source contains in its error circle such an unusual emission-line object.…”

Section: Hd 306414supporting

confidence: 82%

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Unveiling the nature ofINTEGRALobjects through optical spectroscopy

Masetti¹,

Pretorius

Palazzi³

et al. 2006

A&A

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Context. The detection, thanks to the INTEGRAL satellite, of a number of new hard X-ray sources calls for the identification of their nature by means of observations at longer wavelengths. Aims. In our continuing campaign to identify longer-wavelength counterparts of these newly-discovered hard X-ray sources detected by INTEGRAL, we observed the putative optical counterparts of seven southern sources at the South African Astronomical Observatory and at the European Southern Observatory. Methods. Optical spectroscopy was performed on all candidates of these X-ray sources. For two of these objects, optical photometry was also acquired. Results. These observations firmly established the nature of four of these sources: we found that IGR J10404−4625 (=LEDA 93974), 4U 1344−60 and IGR J16482−3036 are Active Galactic Nuclei (AGNs) at redshifts z = 0.0237, 0.013 and 0.0313, respectively, and that 2RXP J130159.6−635806 is a Galactic High-Mass X-ray Binary (HMXB). We also give possible optical identifications for three further objects, namely IGR J11215−5952, IGR J11305−6256 and IGR J16207−5129, which are consistent with being Galactic HMXBs. Physical parameters for these objects are also evaluated by collecting and discussing the available multiwavelength information. Conclusions. The detection of four definite or likely HMXBs out of seven objects in our sample further stresses INTEGRAL's crucial contribution in hunting this class of object. Also, the determination of the extragalactic nature of a substantial fraction of the INTEGRAL survey sources underlines the importance of hard X-ray observations for the study of background AGNs located beyond the "Zone of Avoidance" of the Galactic Plane.

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Section: Hd 306414supporting

confidence: 82%

“…The source was not detected in the 60-200 keV band; this, according to those authors suggests a soft spectrum for the object. As noted by Negueruela et al (2005), the B1 Ia-type supergiant HD 306414 (Vijapurkar & Drilling 1993) lies well inside the INTEGRAL error circle of IGR J11215−5952 (Fig. 1, upper middle panel).…”

Section: The Selected Samplesupporting

confidence: 76%

Unveiling the nature ofINTEGRALobjects through optical spectroscopy

Masetti¹,

Pretorius

Palazzi³

et al. 2006

A&A

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“…References. (F84) Finkenzeller & Mundt (1984); (G06) Gamen et al (2006); (H08) Herbig & Vacca (2008); (H82) Herbst et al (1982); (H76) Herbst & Racine (1976); (H04) Hernández et al (2004); (H92) Hillenbrand et al (1992); (J82) Jones & Herbig (1982); (Mi01) Miroshnichenko et al (2001); (M01) Mora et al (2001); (N95) Nesterov et al (1995); (S90) Shore et al (1990); (T94) Thé et al (1994); (V97) van den Ancker et al (1997); (V98) van den Ancker et al (1998); (V03) Vieira et al (2003); (V11) this paper; (V93) Vijapurkar & Drilling (1993); (W82) Walborn (1982); (W89) Wouterloot & Brand (1989).…”

Section: Notesmentioning

confidence: 84%

A mid-IR study of the circumstellar environment of Herbig Be stars

Verhoeff

Waters

Ancker

et al. 2012

A&A

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Context. The study of the formation of massive stars is complicated because of the short times scales, large distances, and obscuring natal clouds. There are observational and theoretical indications that the circumstellar environment of Herbig Be (HBe) stars is substantially different from that of their lower mass counterparts, the T Tauri and Herbig Ae stars. Aims. We map the spatial distribution and mineralogy of the warm circumstellar dust of a sample of HBe stars. We compare our results to a sample of less massive Herbig Ae stars. Methods. We used literature photometry to obtain optical extinctions and stellar parameters of the targets. We obtained N-band imaging and long-slit spectroscopic data with the VISIR instrument at the VLT and we analyzed these data. We performed photometry of the images and extracted spatial information. We corrected the spectra for extinction and performed mineralogical fits. We fitted Gaussian profiles to characterize the spatial extent of the spectra along the VISIR slit. Results. We find that the mid-infrared (IR) emission of the HBe stars is typically characterized by a circumstellar disk that efficiently reprocesses a substantial portion of the stellar flux. The mid-IR flux levels, the spatial compactness, and the dust composition are quite similar to those of the Herbig Ae stars. We find upper limits to the full-width-at-half-maximum (FWHM) size of the mid-IR emission of ∼500 AU. The main differences with the lower mass stars are the lower overall IR excess with a greater variety in shapes, the weaker PAH reprocessing power, and the lack of a silica-forsterite relation. The discrepancies between VISIR and IRAS photometry, the far-IR contributions and the large PAH sizes of HBe stars are attributed to natal clouds. Conclusions. Our results suggest that the Herbig Be disks are flatter than those around lower mass stars and they are likely truncated from the outside by photoevaporation.

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“…In this way, we classified LS 1132 as a B2IV and LS 1147 as a B0IIIe, previously classified as B3V and B1Ve, respectively. We searched the data about the spectral types of these 63 stars in the "Catalog of Galactic OB Stars" (Reed 2003), and we only found our own references (Corti et al 2003) for the stars in the Luminous Star Catalogue (Stephenson & Sanduleak 1971), together with SpT = O6III (Vijapurkar & Drilling 1993) and O7Vn (Vijapurkar & Drilling 1993) for LS 1135 and LS 1131, respectively. With our spectral classification we are able to test the derivation of basic stellar parameters, such as temperature and observed extinction, from photometric data.…”

Section: Results and Their Discussionmentioning

confidence: 99%

A search for OB stars in the field of the galactic OB association Bochum 7

Corti¹,

Bosch²,

Niemelä³

2007

A&A

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Context. The presence of a Wolf-Rayet star, WR12, at α = 8 h 44 m 47.2 s , δ = −45 • 58 55.5 (J2000.0), triggered the search for a surrounding OB association now known as Bochum 7. Several papers have dealt with the existence of Bo 7, but none actually included spectral types of the stars. To assure the spectral types of members of the association, it is essential to have spectral images of them. Aims. In this paper we present previously unpublished spectra of OB stars over a 30 arcmin field covering the estimated field of the galactic OB association. Methods. From UBV aperture photometry, OB star candidates were selected, and optical spectroscopic observations were obtained for these in CASLEO, Argentina. Results. 63 stars were classified as OB type, including 8 stars already present in the LSS catalogue, and 37 of these 63 stars did not have a well-known spectral type. The OB stars were used to test the properties of the interstellar dust in the line of sight and the relation between the diffuse interestelar band at 4428 Å, which grows linearly with E (B−V) until 1 mag. Combining our data with 2MASS IR photometry we tested and confirmed that derivation of stellar parameters from our photometry, using the CHORIZOS code, is highly reliable.

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MK spectral types for OB(+) stars in the southern Milky Way

Cited by 57 publications

References 0 publications

Unveiling the nature ofINTEGRALobjects through optical spectroscopy

Unveiling the nature ofINTEGRALobjects through optical spectroscopy

A mid-IR study of the circumstellar environment of Herbig Be stars

A search for OB stars in the field of the galactic OB association Bochum 7

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