A medium-bright quasar sample - New quasar surface densities in the magnitude range from 16.4 to 17.65 for B

Mitchell, K. J.; Warnock, A.; Usher, P. D.

doi:10.1086/184384

Cited by 46 publications

(22 citation statements)

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“…Our spectrum (Fig. 7) shows narrow emission lines (F W HM < (Sanduleak & Pesch 1984) is an emission line galaxy (Mitchell et al 1984), and a Seyfert 1.5 galaxy according to Everett & Wagner (1995). This is confirmed by our spectrum (Fig.…”

Section: Observationssupporting

confidence: 85%

Miscellaneous observations of active galactic nuclei. II.

Gonçalves

Véron

Véron-Cetty

1998

Astron. Astrophys. Suppl. Ser.

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Section: Observationssupporting

confidence: 85%

Miscellaneous observations of active galactic nuclei. II.

Gonçalves

Véron

Véron-Cetty

1998

Astron. Astrophys. Suppl. Ser.

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“…Among the most efficient selection methods have been objective-prism surveys. At bright magnitudes, the well-known QSO surveys include the Bright Quasar Survey (Schmidt & Green 1983), the Medium-Bright Quasar Sample (Mitchell, Warnock, & Usher 1984), the Large Bright Quasar Survey (Hewett, Foltz, & Cha †ee 1995), the Homogeneous Bright QSO Survey (La Franca & Cristiani 1997), and the Hamburg/ ÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈ 1 Some of the observations reported here were obtained at the MMT Observatory, a joint facility of the Smithsonian Institution and the University of Arizona. ESO Survey (Wisotzki et al 1996).…”

Section: Introductionmentioning

confidence: 99%

Spectroscopy and Photometry of Stellar Objects from the Second Byurakan Survey

Stepanian

Green

Foltz

et al. 2001

The Astronomical Journal

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The results of spectroscopic observations of 202 stellar objects, and photometric observations of 171, from the Second Byurakan Survey (SBS) are reported. The SBS sample has proved to be a rich source of newly identiÐed quasars, Seyfert-type galaxies, degenerate stars, and hot subdwarfs. In this subsample we have identiÐed 71 new QSOs ; one BL Lacertae object ; one Seyfert 1 galaxy ; one LINER ; one blue compact galaxy ; 31 white dwarfs (WDs), 25 of DA type and six of DB type ; 26 subdwarfs ; 11 horizontal-branch B-type, 11 normal/horizontal-branch, 18 G-type, and 11 F-type stars ; 10 objects with composite spectra ; two cataclysmic variables ; and six objects with continuous spectra. We present accurate positions, spectral classiÐcations, and magnitudes for all objects. The Ó. redshifts, equivalent widths, and spectra for QSOs and emission-line galaxies are given, as are some typical spectra for hot stars. The vast majority (63%) of stellar objects selected in the SBS turned out to be WDs (36%) and sdB subdwarfs (27%). Only D5%È7% of objects with B \ 16.4 and D13% with B D 17.0 were identiÐed as QSOs. In total, 470 QSOs and D500 hot stars were discovered in the course of the SBS. The lower limit on the surface density of bright QSOs in the redshift range 0.3 \ z \ 2.2 is no fewer than 0.06 deg~2 for B \ 17.0 and 0.13 deg~2 for B \ 17.5. The surface density of DA WDs is estimated to be 0.06 deg~2 for B \ 16.0 and 0.14 deg~2 for B \ 17.0.

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“…The net result is an average undercounting by 5%, with a redshift dependence. The Medium Bright Quasar Survey (Mitchell et al 1984) shows a count slope similar to that of the BQS, but a 20% upward displacement in surface density. The cause could be a lower measuring error in magnitude for the BQS, which is unlikely, substantially higher color and accidental errors, or a scale mismatch between the two surveys.…”

mentioning

confidence: 79%

Evolution of the Luminosity Function

Green

1986

Symp. - Int. Astron. Union

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In this review, the currently published, complete, spectroscopically identified samples of quasars are assembled to produce a composite luminosity function, independent of evolutionary assumptions. Two interpretations of the change with cosmic time provide reasonable fits to the data. Luminosity evolution implies a fixed population of host objects, with nuclear luminosity that fades with advancing cosmic time; some dependence of the timescale on intrinsic luminosity is required. Density evolution traces objects of comparable luminosity to find the change in space density, without a requirement of long lifetime. The change in co-moving volume density depends on luminosity; newer data suggest that somewhat stronger evolution is required at the low luminosity end than the models of Schmidt and Green allowed. Caution is advised in drawing direct physical conclusions about the evolution of individual quasars from mathematical representations of ensemble properties.

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A medium-bright quasar sample - New quasar surface densities in the magnitude range from 16.4 to 17.65 for B

Cited by 46 publications

References 0 publications

Miscellaneous observations of active galactic nuclei. II.

Miscellaneous observations of active galactic nuclei. II.

Spectroscopy and Photometry of Stellar Objects from the Second Byurakan Survey

Evolution of the Luminosity Function

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