Search Publications
An Analysis of the Shapes of Interstellar Extinction Curves. V. The IR-through-UV Curve Morphology
Fitzpatrick, E. L.; Massa, D.
We study the IR-through-UV interstellar extinction curves towards 328 Galactic B and late-O stars. We use a new technique which employs stellar atmosphere models in lieu of unreddened "standard" stars. This technique is capable of virtually eliminating spectral mismatch errors in the curves. It also allows a quantitative assessment of the errors a…
Abundances and Behavior of 12CO, 13CO, and C2 in Translucent Sight Lines
York, D. G.; Sonnentrucker, P.; Welty, D. E. +1 more
Using UV spectra obtained with FUSE, HST, and/or IUE together with higher resolution optical spectra, we determine interstellar column densities of 12CO, 13CO, and/or C2 for 10 Galactic sight lines with E(B-V) ranging from 0.37 to 0.72. The N(CO)/N(H2) ratio varies over a factor of 100 in this sample, d…
Warm Gas in the Inner Disks around Young Intermediate-Mass Stars
Simon, Theodore; Najita, Joan R.; Rettig, Terrence W. +1 more
The characterization of gas in the inner disks around young stars is of particular interest because of its connection to planet formation. In order to study the gas in inner disks, we have obtained high-resolution K- and M-band spectroscopy of 14 intermediate-mass young stars. In sources that have optically thick inner disks, i.e., E(K-L)>1, ou…
Hubble Space Telescope Parallaxes of AM CVn Stars and Astrophysical Consequences
Groot, P. J.; McArthur, B. E.; Benedict, G. F. +5 more
We present absolute parallaxes and relative proper motions for five AM CVn stars, which we obtained using the Fine Guidance Sensors on board the Hubble Space Telescope. Our parallax measurements translate into distances dAMCVn=606+135-93 pc, dHPLib=197+14-12 pc, dCRBoo=33…
Elemental abundances of Galactic bulge planetary nebulae from optical recombination lines
Wang, W.; Liu, X. -W.
Deep long-slit optical spectrophotometric observations are presented for 25 Galactic bulge planetary nebulae (GBPNe) and six Galactic disc planetary nebulae (GDPNe). The spectra, combined with archival ultraviolet (UV) spectra obtained with the International Ultraviolet Explorer and infrared spectra obtained with the Infrared Space Observatory, ha…
UV habitable zones around M stars
Buccino, Andrea P.; Lemarchand, Guillermo A.; Mauas, Pablo J. D.
During the last decade there was a change in paradigm, which led to consider that terrestrial-type planets within liquid-water habitable zones (LW-HZ) around M stars can also be suitable places for the emergence and evolution of life. Since many dMe stars emit large amount of UV radiation during flares, in this work we analyze the UV constrains fo…
The escape of Lyman photons from a young starburst: the case of Haro11†
Hayes, Matthew; Östlin, Göran; Leitherer, Claus +5 more
Lyman α (Lyα) is one of the dominant tools used to probe the star-forming galaxy population at high redshift (z). However, astrophysical interpretations of data drawn from Lyα alone hinge on the Lyα escape fraction which, due to the complex radiative transport, may vary greatly. Here, we map the Lyα emission from the local luminous blue compact ga…
The SSS Phase of RS Ophiuchi Observed with Chandra and XMM-Newton. I. Data and Preliminary Modeling
Ness, J. -U.; Gehrz, R. D.; Gonzalez-Riestra, R. +13 more
The phase of supersoft source (SSS) emission of the sixth recorded outburst of the recurrent nova RS Oph was observed on days 39.7 and 66.9 after outburst with Chandra and on day 54.0 with XMM-Newton. A ~35 s period on day 54.0 originates from the SSS emission and not from the shock. We discuss the bound-free absorption by neutral elements in the …
Towards an understanding of the Of?p star HD 191612: optical spectroscopy
Walborn, Nolan R.; Donati, J. -F.; Herrero, A. +17 more
We present extensive optical spectroscopy of the early-type magnetic star HD 191612 (O6.5f?pe-O8fp). The Balmer and He I lines show strongly variable emission which is highly reproducible on a well-determined 538-d period. He II absorptions and metal lines (including many selective emission lines but excluding He IIλ4686 Å emission) are essentiall…
The Disk and Environment of a Young Vega Analog: HD 169142
Ménard, F.; Quirrenbach, A.; Hamaguchi, K. +15 more
We trace the disk of HD 169142 (A8 Ve) from 0.57" to 1.4" (~80-200 AU projected distance) in 1.1 µm scattered light with HST NICMOS coronagraphy. The azimuthally symmetric disk has a peak azimuthally medianed surface brightness (SB) of ~5 mJy arcsec-2 at 0.57" from the star, and drops ~r-3. This radial SB profile is con…