scholarly journals Near Infrared Spectroscopic Observations of Early-type Be Stars

2000 ◽  
Vol 175 ◽  
pp. 468-471 ◽  
Author(s):  
N. M. Ashok ◽  
D. P. K. Banerjee
Keyword(s):  
Emission Line ◽  
Infrared Spectra ◽  
Near Infrared ◽  
Be Stars ◽  
Early Type ◽  
Line Flux ◽  
Near Infrared Spectra ◽  
Medium Resolution ◽  
Significant Strength ◽  
Lower Temperature

AbstractThe medium resolution (R=1000) near infrared spectra of 30 early type Be stars obtained during the period October 1998-April 1999 are presented. The Paschen β and Brackett γ lines are seen in emission in majority of these stars. The higher order Brackett series lines from m=10 to 19 are detected in emission with significant strength compared to the Brackett γ emission line flux indicating the effect of optical depth. The Fe II line at 1.6873μm is detected in a small number of stars indicating existence of higher density and lower temperature emission zone.

scholarly journals A Comparison of Near Infrared Spectra of the Galactic Center He I Emission Line Sources and Early Type Mass Losing Stars

1996 ◽  
Vol 169 ◽  
pp. 225-230
Author(s):  
R. D. Blum ◽  
D. L. Depoy ◽  
K. Sellgren
Keyword(s):  
Emission Line ◽  
Infrared Spectra ◽  
Near Infrared ◽  
Galactic Center ◽  
Early Type ◽  
Near Infrared Spectra ◽  
Wide Range ◽  
Comparison Stars ◽  
Band Spectra ◽  
Type Mass

We have obtained R ≈ 570 resolution K band spectra of eight sources in the Galactic Center, including four sources within the IRS 16 cluster, IRS 13, IRS 1W, and the compact He I emission line sources AF (also known as AHH) and AHH NW. We have also obtained R ≈ 570 H and K band spectra of nine galactic and LMC early–type mass–losing stars, including Ofpe/WN9 and WN stars. The spectra of both the Galactic Center sources and the comparison stars show a wide range of behavior in the He I (1.70 μm, 2.06 μm, 2.11 μm) and H I (Brackett series) lines. We find significantly larger He I equivalent widths in the AF source and two galactic early type mass losing stars than in any of the LMC stars. Several of the Galactic Center He I sources are found to have higher He I velocity widths than any of the galactic or LMC early type mass losing stars. At least one source, IRS 13, shows a strong red wing to the He I 2.06 μm emission.

scholarly journals Near Infrared Spectra of 103 Bright Be Stars

1987 ◽  
Vol 92 ◽  
pp. 237-238
Author(s):  
Y. Andrillat
Keyword(s):  
Spectral Range ◽  
Infrared Spectra ◽  
Near Infrared ◽  
High Dispersion ◽  
Be Stars ◽  
Near Infrared Spectra ◽  
Low Dispersion

We have observed 103 bright Be stars in the near infrared up to 10500 A with a dispersion of 230 and 50 A mm-1. The observations were performed with a Reticon (1024 diodes) attached to the ROUCAS spectrograph at the 193 cm telescope of the Haute Provence Observatory.In this spectral range, the Be stars are characterized by the lines of HI (Paschen series), 0I(7772-74-75, 8446 A), CaII(8542, 8662, 8498 A), FeII(7712, 9997 A) and NI(8686-83-80, 8719-12-03, 8629 A).On our spectra, the CaII triplet is always blended with P13, P15, P16, and only the enhancement of these lines permits to conclude to the CaII presence. The 0I 8446 A is perturbed by the Paschen lines P17 and P18 (low dispersion spectra) and P18 (high dispersion spectra). The NI 8686-83-80 A lines also perturb the P13 profile.

scholarly journals Medium resolution near-infrared spectra of the host galaxies of nearby quasars

2014 ◽  
Vol 54 (6) ◽  
pp. 1129-1134 ◽  
Author(s):  
Huynh Anh Nguyen Le ◽  
Soojong Pak ◽  
Myungshin Im ◽  
Minjin Kim ◽  
Chae Kyung Sim ◽  
...  
Keyword(s):  
Infrared Spectra ◽  
Near Infrared ◽  
Host Galaxies ◽  
Near Infrared Spectra ◽  
Medium Resolution

scholarly journals Near Infrared Spectra of Southern Be Stars

1987 ◽  
Vol 92 ◽  
pp. 239-241
Author(s):  
L. Pastori
Keyword(s):  
Infrared Spectra ◽  
Spectral Type ◽  
Near Infrared ◽  
Infrared Region ◽  
Bright Star ◽  
Be Stars ◽  
Star Catalogue ◽  
Near Infrared Spectra ◽  
Near Infrared Region ◽  
Right Ascension

Spectra of northern Be stars in the near infrared region have been already described by some authors (see Slettebak, 1979 for a brief review). This paper presents general results for southern Be stars obtained from more than 100 spectrograms in the region λλ7750-9000 Å the spectra were taken in four nights of February 1985 at the 1.5m ESO telescope with the reticon instrumentation; the dispersion is 58 Åmm-1. All the available southern Be stars (right ascension between 4h and 17h) listed in the Bright Star Catalogue (Hoffleit and Jaschek, 1982) were observed. Table 1 lists the number of stars vs. spectral type (columns 1 and 2) and the number of stars which display emission at the Paschen series, 0I λ8446 Å and Call triplet (columns 3 to 5).

scholarly journals The Origin of Weak Emission-Line AGNs

2012 ◽  
Vol 8 (S290) ◽  
pp. 267-268
Author(s):  
Yuan Liu ◽  
Jin Zhang ◽  
Shuang-Nan Zhang
Keyword(s):  
Emission Line ◽  
Optical Spectroscopy ◽  
Infrared Spectra ◽  
Near Infrared ◽  
Early Stage ◽  
Optical Emission ◽  
Emission Lines ◽  
Near Infrared Spectra

AbstractSome abnormal AGNs are discovered in the SDSS data recently. The usual UV/optical emission lines are exceptionally weak in their UV/optical spectroscopy, though the shapes and luminosities of their continua are comparable with that of the normal AGNs. We investigated the optical variations and the near-infrared spectra of these weak emission-line AGNs. We propose that these AGNs can be interpreted as the early stage of an active cycle of AGNs.

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