Zobrazeno 1 - 10
of 58
pro vyhledávání: '"Foltz, C. B."'
Publikováno v:
Astron.J.132:2046-2073,2006
We present spectroscopic observations for quasars Q0107-025A, Q0107-025B, and Q0107-0232. For the first time, all data obtained with the Hubble Space Telescope's GHRS and FOS for these three quasars are combined. Ly-alpha absorbers selected from the
Externí odkaz:
http://arxiv.org/abs/astro-ph/0610350
Publikováno v:
Astrophys.J. 578 (2002) L99-L102
An infrared-selected, narrow-line QSO has been found to exhibit an extraordinarily broad Halpha emission line in polarized light. Both the extreme width (35,000 km/sec full-width at zero intensity) and 3,000 km/sec redshift of the line centroid with
Externí odkaz:
http://arxiv.org/abs/astro-ph/0209277
Autor:
Dietrich, M., Hamann, F., Shields, J. C., Constantin, A., Vestergaard, M., Chaffee, F., Foltz, C. B., Junkkarinen, V. T.
Publikováno v:
Astrophys.J. 581 (2002) 912-924
We report on the analysis of a large sample of 744 type 1 Active Galactic Nuclei, including quasars and Seyfert 1 galaxies across the redshift range from 0 < z < 5 and spanning nearly 6 orders of magnitude in continuum luminosity. We discuss correlat
Externí odkaz:
http://arxiv.org/abs/astro-ph/0208348
Publikováno v:
Astrophys.J.574:623-633,2002
We present spectroscopic observations with Keck/LRIS of LBQS 0015+0239, a pair of quasars at z = 2.45 with a separation of $\Delta\theta = 2.2$ arcsec (projected linear distance of 17.8 $h_{70}^{-1}$ kpc, for $\Omega_m = 0.3$, $\Lambda = 0.7$). Lensi
Externí odkaz:
http://arxiv.org/abs/astro-ph/0204084
Autor:
Zurita, C., Casares, J., Shahbaz, T., Wagner, R. M., Foltz, C. B., Rodriguez-Gil, P., Hynes, R. I., Charles, P. A., Ryan, E., Schwarz, G., Starrfield, S. G.
Publikováno v:
Mon.Not.Roy.Astron.Soc. 333 (2002) 791
We present the results of our monitoring of the halo black-hole soft X-ray transient (SXT) XTE J1118+480 during its decline to quiescence. The system has decayed 0.5 mags from December 2000 to its present near quiescent level at R=18.65 (June 2001).
Externí odkaz:
http://arxiv.org/abs/astro-ph/0202438
Autor:
Guseva, N. G., Izotov, Y. I., Papaderos, P., Chaffee, F. H., Foltz, C. B., Green, R. F., Thuan, T. X., Fricke, K. J., Noeske, K. G.
Publikováno v:
Astron.Astrophys.378:756-776,2001
We present the results of spectrophotometry and V,R,I, Halpha CCD photometry of the blue compact dwarf (BCD) galaxy SBS 0940+544. Broad-band images taken with the 2.1m KPNO and 1.23m Calar Alto telescopes reveal a compact high-surface-brightness H II
Externí odkaz:
http://arxiv.org/abs/astro-ph/0109256
Autor:
Izotov, Y. I., Chaffee, F. H., Foltz, C. B., Thuan, T. X., Green, R. F., Papaderos, P., Fricke, K. J., Guseva, N. G.
Publikováno v:
Astrophys.J.560:222-235,2001
Long-slit Keck II, 4m Kitt Peak, and 4.5m MMT spectrophotometric data are used to investigate the stellar population and the evolutionary status of I Zw 18C, the faint C component of the nearby blue compact dwarf galaxy I Zw 18. Hydrogen H$\alpha$ an
Externí odkaz:
http://arxiv.org/abs/astro-ph/0109257
Publikováno v:
ASP Conf.Ser.255:137-142,2002
We discuss new high-resolution (6.7 km/s) spectra of the associated absorption lines (AALs) in the radio-loud quasar 3C 191. The measured AALs have ionizations ranging from Mg I to N V, and multi-component profiles that are blueshifted by ~400 to ~14
Externí odkaz:
http://arxiv.org/abs/astro-ph/0105337
Autor:
Wagner, R. M., Foltz, C. B., Shahbaz, T., Casares, J., Charles, P. A., Starrfield, S. G., Hewett, P.
Publikováno v:
Astrophys.J.556:42-46,2001
Optical spectra were obtained of the optical counterpart of the high latitude soft X-ray transient XTE J1118+480 near its quiescent state with the new 6.5 m MMT and the 4.2 m WHT. The spectrum exhibits broad, double-peaked, emission lines of hydrogen
Externí odkaz:
http://arxiv.org/abs/astro-ph/0104032
Publikováno v:
Astrophys.J.550:142-152,2001
Associated absorption lines (AALs) are valuable probes of the gaseous environments near quasars. Here we discuss high-resolution (6.7 km/s) spectra of the AALs in the radio-loud quasar 3C 191 (redshift z=1.956). The measured AALs have ionizations ran
Externí odkaz:
http://arxiv.org/abs/astro-ph/0011030