Zobrazeno 1 - 10
of 160
pro vyhledávání: '"Green, R F"'
Quasar luminosity functions are a fundamental probe of the growth and evolution of supermassive black holes. Measuring the intrinsic luminosity function is difficult in practice, due to a multitude of observational and systematic effects. As sample s
Externí odkaz:
http://arxiv.org/abs/1404.3151
X-ray loud M dwarfs are a major source of by-product (contamination) in the X-ray band of the multiwavelength quasar survey (MWQS). As a by-product, the low dispersion spectra of 22 M dwarfs are obtained in which the spectra of 16 sources are taken f
Externí odkaz:
http://arxiv.org/abs/1201.1359
Autor:
Fechner, C., Reimers, D., Kriss, G. A., Baade, R., Blair, W. P., Giroux, M. L., Green, R. F., Moos, H. W., Morton, D. C., Scott, J. E., Shull, J. M., Simcoe, R., Songaila, A., Zheng, W.
We present the far-UV spectrum of the quasar HS1700+6416 taken with FUSE. This QSO provides the second line of sight with the HeII absorption resolved into a Ly alpha forest structure. Since HS1700+6416 is slightly less redshifted (z=2.72) than HE234
Externí odkaz:
http://arxiv.org/abs/astro-ph/0605150
Many EHB stars have been found in short-period binaries, where the companions in these post-common envelope systems are either white dwarfs or dM stars; these systems are catalogued as hot subdwarfs because the subdwarf is the more luminous component
Externí odkaz:
http://arxiv.org/abs/astro-ph/0511403
Publikováno v:
ASP Conf.Ser. 334 (2005) 123
The Palomar-Green (PG) survey for UV-excess objects selected objects with U-B<-0.46 for spectroscopic follow-up. The color selection was done from photographic photometry, with typical error sigma_(U-B)=0.38. Spectroscopic detection of the Ca II K li
Externí odkaz:
http://arxiv.org/abs/astro-ph/0410287
Autor:
Guseva, N. G., Papaderos, P., Izotov, Y. I., Green, R. F., Fricke, K. J., Thuan, T. X., Noeske, K. J.
Publikováno v:
Astron.Astrophys. 407 (2003) 91-104
We present broad-band V and I imaging and long-slit spectroscopy in the optical range 3600-7500A of the dwarf irregular galaxy HS 1442+4250. The oxygen abundance 12+log(O/H)=7.63+/-0.02 (Z=Zsun/19) in the brightest H II region of HS 1442+4250 places
Externí odkaz:
http://arxiv.org/abs/astro-ph/0306166
Autor:
Guseva, N. G., Papaderos, P., Izotov, Y. I., Green, R. F., Fricke, K. J., Thuan, T. X., Noeske, K. J.
Publikováno v:
Astron.Astrophys. 407 (2003) 105-120
We present a detailed optical spectroscopic and B,V,I,Halpha photometric study of the metal-deficient cometary blue compact dwarf (BCD) galaxy SBS 1415+437. We derive an oxygen abundance 12+log(O/H)=7.61+/-0.01 and 7.62+/-0.03 (Z =Zsun/20) in the two
Externí odkaz:
http://arxiv.org/abs/astro-ph/0306167
Autor:
Kriss, G. A., Blustin, A., Branduardi-Raymont, G., Green, R. F., Hutchings, J., Kaiser, M. E.
Publikováno v:
Astron.Astrophys. 403 (2003) 473-480
We obtained far-ultraviolet spectra of the Seyfert 1 galaxy NGC 7469 using the FUSE on 1999 December 6. Our spectra cover the wavelength range 990-1187 A with a resolution of 0.05 A. We see broad emission lines of CIII, NIII, OVI, and HeII as well as
Externí odkaz:
http://arxiv.org/abs/astro-ph/0302552
Autor:
Tripp, T. M., Wakker, B. P., Jenkins, E. B., Bowers, C. W., Danks, A. C., Green, R. F., Heap, S. R., Joseph, C. L., Kaiser, M. E., Linsky, J. L., Woodgate, B. E.
(Abridged) We present a new high-resolution (7 km/s FWHM) echelle spectrum of 3C 351 obtained with STIS. 3C 351 lies behind the low-latitude edge of high-velocity cloud Complex C, and the new spectrum provides accurate measurements of O I, Si II, Al
Externí odkaz:
http://arxiv.org/abs/astro-ph/0302534
Autor:
Monier, E. M., Kennefick, J. D., Hall, P. B., Osmer, P. S., Smith, M. G., Dalton, G. B., Green, R. F.
The BTC40 Survey for high-redshift quasars is a multicolor search using images obtained with the Big Throughput Camera (BTC) on the CTIO 4-m telescope in V, I, and z filters to search for quasars at redshifts of 4.8 < z < 6. The survey covers 40 sq.
Externí odkaz:
http://arxiv.org/abs/astro-ph/0209055