Optical spectra of four objects identified with variable radio sources

Chavushyan, V.; Mújica, R.; Gorshkov, A. G.; Konnikova, V. K.; Мингалиев, М. Г.

doi:10.1134/1.20400

Cited by 4 publications

(7 citation statements)

References 7 publications

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“…The source can be identified as a BL Lac (the optical spectrum contains no emission lines, Chavushyan et al 2000). A flux density variability on a time scale less than 10 days was found in the simultaneous observations carried out with the RATAN-600 radio telescope in 1998 (Figure 1).…”

Section: Introduction Observations and Resultsmentioning

confidence: 93%

VLBI and Broad-Band Radio Spectra Study of the Strongly Variable Extragalactic Object 0524+034

Kovalev¹,

Gorshkov²,

Konnikova³

et al. 2001

Symp. - Int. Astron. Union

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Abstract. Results of the first measurements of a VLBI structure of 0524+034 at 6 em at the EVN+HartRAO in 1999 and recent broad-band spectra monitoring data are reported. We suppose that precession of the relativistic jet can be one of the possible mechanisms to account for the observed milliarcsecond structure and the strong long-term variations of the spectrum. The detected rapid changes may be interpreted as a propagation of a shock in the inhomogeneous jet plasma, but interstellar scintillations can not be ruled out on the basis of available data.

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Section: Introduction Observations and Resultsmentioning

confidence: 93%

VLBI and Broad-Band Radio Spectra Study of the Strongly Variable Extragalactic Object 0524+034

Kovalev¹,

Gorshkov²,

Konnikova³

et al. 2001

Symp. - Int. Astron. Union

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“…m 5 (Stepanian, 1994). For some objects the photometric B magnitudes with two decimals are given, those should have a probable error of 0. m 05, (Chavushyan et al 1995, 5 -the spectral type, 6 -date of observation, 7 -exposure time, 8 -instrument used, 9 -an alternative designation of the object when available.…”

Section: The Resultsmentioning

confidence: 99%

“…In the present paper we report the results of spectroscopic observations of 363 relatively bright stellar objects from the SBS sample. The observational data were obtained at the Special Astrophysical Observatory (Russia) and Guillermo Haro Observatory (GHO) of the INAOE in Cananea (Mexico).The BV CCD photometric data for confirmed QSOs were obtained with the 1 m telescope at SAO (Chavushyan et al 1995.…”

Section: Introductionmentioning

confidence: 99%

Spectroscopy of Stellar‐like Objects Contained in the Second Byurakan Survey. I.

Stepanian

Chavushyan

Carrasco

et al. 1999

PUBL ASTRON SOC PAC

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The results of spectroscopic observations of 363 star-like objects from the Second Byurakan Survey (SBS) are reported. This SBS's subsample has proven to be a rich source of newly identified quasars, Seyfert type galaxies, degenerate stars and hot subdwarfs. In the subsample here studied, we identified 35 new QSOs, 142 White Dwarfs (WDs) the majority of which, 114 are of DA type, 55 subdwarfs (29 of which are sdB-type stars), 10 HBB, 16 NHB, 54 G-type and 25 F-type stars, two objects with composite spectra, four Cataclismic Variables (CV), two peculiar emission line stars, 17 objects with continuous spectra, as well as one planetary nebula. Among the 35 QSOs we have found two Broad Absorption Line (BAL) QSOs, namely SBS 1423+500 and SBS 1435+500A. Magnitudes, redshifts, and slit spectra for all QSOs, also some typical spectra of the peculiar stars are presented. We estimate the minimum surface density of bright QSOs in redshift range 0.3 < z < 2.2 to be 0.05 per sq. deg. for B < 17. m 0 and 0.10 per sq. deg. for B < 17. m 5.

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“…This X-ray selected object (Voges et al 1999) was classified as a BLL by Schwope et al (2000). The optical spectrum reported by Chavushyan et al (2000) was featureless. Our VLT spectrum shows faint absorption lines from the BLL host galaxy (CaII λλ3934,3968, G band λ4305, and MgI λ5175) at z = 0.243.…”

Section: Rbs 1915mentioning

confidence: 98%

“…This radio selected source (Large et al 1981) was classified as a BL Lac because of its flat radio spectrum and the featureless optical spectrum (Chavushyan et al 2000 Bressan et al 2006). A measurement of the equivalent width of the Hα+[NII] line system (which is out of the observed spectral range) could help to clarify this issue.…”

Section: Txs 2346+052mentioning

confidence: 99%

European Southern Observatory Very Large Telescope Optical Spectroscopy of Bl Lacertae Objects. Iii. An Extension of the Sample

Sbarufatti

Ciprini

Kotilainen

et al. 2008

The Astronomical Journal

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We present results of an ongoing program at the ESO VLT for spectroscopy of BL Lac objects lacking a firm redshift estimate and here we report on 15 objects. For 11 sources we confirm the BL Lac classification, and we determine new redshifts for 3 objects, 1 with weak emission lines (PKS 1057−79, z = 0.569) and 2 with absorptions from the host galaxy (RBS 1752, z = 0.449; RBS 1915, z = 0.243); moreover a sub Damped Lyman Alpha (sub-DLA) system is detected in the direction of the BL Lac PKS 0823−223 (z ≥ 0.911). For the remaining 8 BL Lacs, from the very absence of absorption lines of the host galaxy, lower limits to the redshift are deduced with z min in the interval 0.20 − 0.80. The remaining three sources are reclassified as a FSRQ (PKS 1145−676, z = 0.210; TXS 2346+052, z = 0.419) and a misclassified galactic star (PMNJ 1323−3652).

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Optical spectra of four objects identified with variable radio sources

Cited by 4 publications

References 7 publications

VLBI and Broad-Band Radio Spectra Study of the Strongly Variable Extragalactic Object 0524+034

VLBI and Broad-Band Radio Spectra Study of the Strongly Variable Extragalactic Object 0524+034

Spectroscopy of Stellar‐like Objects Contained in the Second Byurakan Survey. I.

European Southern Observatory Very Large Telescope Optical Spectroscopy of Bl Lacertae Objects. Iii. An Extension of the Sample

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