scholarly journals The D/H Ratio in Interstellar Gas toward the Hot, White Dwarf G191-B2B

2000 ◽  
Vol 198 ◽  
pp. 161-166
Author(s):  
M. S. Sahu
Keyword(s):  
High Resolution ◽  
White Dwarf ◽  
New Work ◽  
Interstellar Gas ◽  
Space Telescope ◽  
Imaging Spectrograph

Space Telescope Imaging Spectrograph (STIS) observations of the D/H ratio in the two velocity components towards G191-B2B are consistent with 1.5 ± 0.1 × 10−5 and do not agree with the values derived using the Goddard High Resolution Spectrograph (GHRS) data. We present some new work on the G191-B2B sightline, and the results we obtain are consistent with those of Sahu et al. (1999).

scholarly journals White Dwarf Probes of Interstellar Deuterium

2000 ◽  
Vol 198 ◽  
pp. 485-486
Author(s):  
Wayne Landsman
Keyword(s):  
High Resolution ◽  
Interstellar Medium ◽  
White Dwarf ◽  
White Dwarfs ◽  
Accurate Determination ◽  
The Sun ◽  
Local Interstellar Medium ◽  
Space Telescope ◽  
Imaging Spectrograph

We review the advantages of using hot white dwarfs (WDs) as probes of the deuterium abundance in the local interstellar medium. We then discuss advantages of the Space Telescope Imaging Spectrograph (STIS) for such observations, as compared with earlier observations with the Goddard High Resolution Spectrograph (GHRS). The GHRS Ly α profile of the white dwarf HZ 43 is probably modified by the hot ‘hydrogen wall’ surrounding the Sun; but despite this complication, the sightline remains a promising one for an accurate determination of the deuterium abundance in the local interstellar medium.

scholarly journals The Interstellar Abundance of Lead: Experimental Oscillator Strengths for Pb ii λ1203 and λ1433 and New Detections of Pb ii in the Interstellar Medium

2015 ◽  
Vol 11 (A29A) ◽  
Author(s):  
A. M. Ritchey ◽  
N. Heidarian ◽  
R. E. Irving ◽  
S. R. Federman ◽  
D. G. Ellis ◽  
...  
Keyword(s):  
Interstellar Medium ◽  
Hubble Space Telescope ◽  
Oscillator Strengths ◽  
Interstellar Gas ◽  
Lifetime Measurements ◽  
Space Telescope ◽  
Interstellar Grains ◽  
Imaging Spectrograph ◽  
Theoretical Results ◽  
Beam Foil

AbstractWe present the first experimentally determined oscillator strengths for the Pb ii transitions at 1203.6 Å and 1433.9 Å, obtained from lifetime measurements made using beam-foil techniques. We also present new detections of these lines in the interstellar medium from an analysis of archival spectra acquired by the Space Telescope Imaging Spectrograph onboard the Hubble Space Telescope. Our observations of the Pb ii λ1203 line represent the first detection of this transition in interstellar gas. Our experimental f-values for the Pb ii λ1203 and λ1433 transitions are consistent with recent theoretical results, including our own relativistic calculations, but are significantly smaller than previous values based on older calculations. Our new f-value for Pb ii λ1433 (0.321 ± 0.034) yields an increase in the interstellar abundance of Pb of 0.43 dex over estimates based on the f-value listed by Morton. With our revised f-values, and with our new detections of Pb ii λ1203 and λ1433, we find that the depletion of Pb onto interstellar grains is not nearly as severe as previously thought, and is very similar to the depletions seen for elements such as Zn and Sn, which have similar condensation temperatures.

scholarly journals STIS Coronagraphic Observations of β Pictoris

2004 ◽  
Vol 202 ◽  
pp. 338-340
Author(s):  
S. R. Heap ◽  
D. J. Lindler ◽  
T. M. Lanz
Keyword(s):  
High Resolution ◽  
Spectral Region ◽  
Hubble Space Telescope ◽  
Space Telescope ◽  
High Resolution Images ◽  
Imaging Spectrograph

We present recent coronagraphic observations of β Pictoris obtained with the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope. The superb, high-resolution images show that the inner part of the disk is inclined by about 5° with respect to the main disk. Long-slit coronagraphic spectrograms oriented along the inner disk indicate that the reflectance of the inner disk is neutral over the spectral region, 3000-5600 Å.

Far‐Ultraviolet Space Telescope Imaging Spectrograph Spectra of the White Dwarf REJ 1032+532. II. Stellar Spectrum

1999 ◽  
Vol 517 (2) ◽  
pp. 850-858 ◽  
Author(s):  
J. B. Holberg ◽  
M. A. Barstow ◽  
F. C. Bruhweiler ◽  
I. Hubeny ◽  
E. M. Green
Keyword(s):  
White Dwarf ◽  
Stellar Spectrum ◽  
Space Telescope ◽  
Far Ultraviolet ◽  
Imaging Spectrograph

scholarly journals HST/STIS transmission spectrum of the ultra-hot Jupiter WASP-76 b confirms the presence of sodium in its atmosphere

2020 ◽  
Vol 637 ◽  
pp. A76 ◽  
Author(s):  
C. von Essen ◽  
M. Mallonn ◽  
S. Hermansen ◽  
M. C. Nixon ◽  
N. Madhusudhan ◽  
...  
Keyword(s):  
High Resolution ◽  
Transmission Spectrum ◽  
Rayleigh Scattering ◽  
Equilibrium Temperature ◽  
Atmospheric Transmission ◽  
Space Telescope ◽  
Atomic Sodium ◽  
The One ◽  
Imaging Spectrograph ◽  
Hot Jupiter

We present an atmospheric transmission spectrum of the ultra-hot Jupiter WASP-76 b by analyzing archival data obtained with the Space Telescope Imaging Spectrograph (STIS) on board the Hubble Space Telescope (HST). The dataset spans three transits, two with a wavelength coverage between 2900 and 5700 Å, and the third one between 5250 and 10 300 Å. From the one-dimensional, time dependent spectra we constructed white and chromatic light curves, the latter with typical integration band widths of ~200 Å. We computed the wavelength dependent planet-to-star radii ratios taking into consideration WASP-76’s companion. The resulting transmission spectrum of WASP-76 b is dominated by a spectral slope of increasing opacity towards shorter wavelengths of amplitude of about three scale heights under the assumption of planetary equilibrium temperature. If the slope is caused by Rayleigh scattering, we derive a lower limit to the temperature of ~870 K. Following-up on previous detection of atomic sodium derived from high resolution spectra, we re-analyzed HST data using narrower bands centered around sodium. From an atmospheric retrieval of this transmission spectrum, we report evidence of sodium at 2.9σ significance. In this case, the retrieved temperature at the top of the atmosphere (10−5 bar) is 2300−392+412 K. We also find marginal evidence for titanium hydride. However, additional high resolution ground-based data are required to confirm this discovery.

The Stellar Content of Henize 2‐10 from Space Telescope Imaging Spectrograph Ultraviolet Spectroscopy

2003 ◽  
Vol 586 (2) ◽  
pp. 939-958 ◽  
Author(s):  
Rupali Chandar ◽  
Claus Leitherer ◽  
Christy Tremonti ◽  
Daniela Calzetti
Keyword(s):  
Ultraviolet Spectroscopy ◽  
Stellar Content ◽  
Space Telescope ◽  
Imaging Spectrograph
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