A5040695603- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Atomic and Molecular Physics
- Gamma-ray bursts and supernovae
- Laser-induced spectroscopy and plasma
- History and Developments in Astronomy
- Spectroscopy and Laser Applications
- Atmospheric Ozone and Climate
- Astrophysical Phenomena and Observations
- Solar and Space Plasma Dynamics
- Astronomical and nuclear sciences
- Adaptive optics and wavefront sensing
- Nuclear physics research studies
- Calibration and Measurement Techniques
- Atomic and Subatomic Physics Research
- Advanced Chemical Physics Studies
- Advanced Frequency and Time Standards
- Nuclear Physics and Applications
- Galaxies: Formation, Evolution, Phenomena
- Inertial Sensor and Navigation
- Pulsars and Gravitational Waves Research
- X-ray Spectroscopy and Fluorescence Analysis
Space Telescope Science Institute
1989-2025
Michigan Science Center
2022
General Dynamics (United States)
2018
Catholic University of America
1999-2014
University of America
2008-2014
National Astronomical Observatories
2013
Chinese Academy of Sciences
2013
Goddard Space Flight Center
1993-2012
Lund University
1999-2009
National Institute of Standards and Technology
2008
Abstract The Near-Infrared Spectrograph (NIRSpec) is one of the four focal plane instruments on James Webb Space Telescope. In this paper, we summarize in-orbit performance NIRSpec, as derived from data collected during its commissioning campaign and first few months nominal science operations. More specifically, discuss some critical hardware components such two NIRSpec Hawaii-2RG detectors, wheel mechanisms, microshutter array. We also accuracy target acquisition procedures used to...
We summarize here the results of a major eight-year investigation extraordinarily detailed UV spectrum sharp-lined, nonmagnetic, main-sequence, chemically peculiar star χ Lupi (B9.5p HgMn + A2 Vm). The observations are composed 345 Å acquired with Goddard High Resolution Spectrograph (GHRS) on board Hubble Space Telescope at an average resolution 0.023 Å. complete set echelle spectrograms is presented as atlas in companion paper. These data were supplemented by optical-wavelength spectra...
Context. V407 Cyg was, before 2010 Mar., known only as a D-type symbiotic binary system in which the Mira variable has pulsation period of approximately 750 days, one longest known. On Mar. 10, it was discovered outburst, eventually reaching V < 8. This is first recorded nova event for this system, but closely resembles spectroscopic development RS Oph, prototypical symbiotic-like recurrent nova. It also detected by Fermi above 100 MeV and displayed strong, likely nonthermal centimeter...
The spectra of singly and doubly ionized praseodymium have been observed by means Fourier transform spectroscopy in the region 2800–8000 Å. In Pr II improved wavelengths are reported for 49 lines. For 31 lines gf-values determined branching fractions combined with recently measured lifetimes. hyperfine structure patterns analyzed 44 lines, magnetic constants A derived 8 odd 18 even levels. Using transitions energy levels reported. Accurate given 15 strong III. from this study applied to...
The Goddard High Resolution Spectrograph (GHRS) on the Hubble Space Telescope (HST) is producing ultraviolet spectra of unprecedented resolution and photometric quality. We illustrate this with observations ultra-sharp-lined, chemically peculiar B-type star, χ Lupi. photosphere star rich in heavy elements, its UV spectrum replete transitions species not commonly observed astrophysical spectra. It an excellent "laboratory" for atomic spectroscopy. Wavelengths measured GHRS are accurate to...
The in-orbit performance of the Goddard High Resolution Spectrograph onboard Hubble Space Telescope (HST) is presented. This report covers pre-COSTAR period, when instrument was limited by effects spherical aberration telescope's primary mirror. digicon detectors provide a linear response to count rates spanning over six orders magnitude, ranging from normal background flux 0.01 counts diode -1 s-1 values larger than 104 diode-1 s-1. Scattered light first-order gratings small and can be...
view Abstract Citations (74) References (19) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS First Results from the Goddard High-Resolution Spectrograph: Observations of 1942 Angstrom Resonance Line HG II in Chemically Peculiar B Star, chi LUPI Leckrone, David S. ; Wahlgren, Glenn M. Johansson, Sveneric G. The Spectrograph on HST has been used to obtain high S/N observations sharp-lined, Hg- and Pt-rich B-type star, Chi Lupi, with a resolving power 87,000....
Context. New instrumental capabilities and the wealth of astrophysical information extractable from near-infrared wavelength region have led to a growing interest in field high resolution spectroscopy at 1–5 μm.
Observations of mercury lines in the HgMn stars χ Lupi and HR 7775 made with Hubble Space Telescope Goddard High Resolution Spectrograph are presented analyzed. In we find that all observed consistent same isotopic mixture (essentially pure 204Hg). Strong ionization anomalies present, UV Hg I being too weak III strong for abundance derived from majority state, II. show less extreme isotope anomalies. We anomaly resonance can be plausibly explained as a non-LTE effect, but calculations cannot...
view Abstract Citations (58) References (73) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Abundances of Pt, Au, and HG in the Chemically Peculiar HgMn-Type Stars kappa CANCRI chi LUPI Wahlgren, Glenn M. ; Leckrone, David S. Johansson, Sveneric G. Rosberg, Maria Brage, Tomas Echelle mode spectra obtained with Goddard High Resolution Spectrograph (GHRS) onboard Hubble Space Telescope (HST) have been used to determine abundances heavy elements Hg...
The NIRSpec instrument on the James Webb Space Telescope (JWST) brings first multi-object spectrograph (MOS) into space, enabled by a programmable Micro Shutter Array (MSA) of ∼250,000 individual apertures. During 6-month Commissioning period, MSA performed admirably, completing ∼800 reconfigurations with an average success rate ∼96% for commanding shutters open in science-like patterns. We show that 82.5% unvignetted shutter population is usable science, electrical short masking now primary...
Optical region spectra of 31 HgMn stars have been studied for the abundance and isotope mixture mercury. In course investigation lines λ4358 λ λ3984,6149 studied, with abundances established all three in several stars. The mercury has determined from high resolution λ3984 line. Possible signs an ionization anomaly detected by comparison derived line seven observed A possible correlation detected. a weak anticorrelation manganese found, which could be interpreted as sign inhomogeneous surface...
In this paper we demonstrate how Stromgren uvby photometry can be efficiently used to: 1. Identify red giant branch stars that are members in a dwarf spheroidal galaxy. 2. Derive age-independent metallicities for the same and quantify associated errors. 11 x 22 arcmin field centered on Draco galaxy was obtained using Isaac Newton Telescope La Palma. Members of dSph were identified surface gravity sensitive c_1 index which discriminates between stars. Thus enabling us to distinguish (red...
HD 65949 is a late B star with exceptionally strong Hg ii λ3984, but it not typical HgMn star. The Re spectrum of extraordinary strength. Abundances or upper limits are derived here for 58 elements based on model Teff= 13 100 K and log (g) = 4.0. Even-Z through nickel show minor deviations from solar abundances. Anomalies among the odd-Z copper mostly small. Beyond iron peak, huge scatter found. Enormous enhancements found rhenium mercury (Z= 75–80). We note presence Th iii in spectrum....
view Abstract Citations (56) References (54) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS GHRS Observations of Cool, Low-Gravity Stars. I. The Far-Ultraviolet Spectrum alpha Orionis (M2 Iab) Carpenter, Kenneth G. ; Robinson, Richard D. Wahlgren, Glenn M. Linsky, Jeffrey L. Brown, Alexander We present far-UV (1200-1930 A) observations the prototypical red supergiant star Ori, obtained with Goddard High Resolution Spectrograph (GHRS) on Hubble Space...
Radiative lifetimes of two levels in Ce I, eight II, and nine III have been measured using the time-resolved laser-induced fluorescence technique. Free cerium atoms singly doubly ionized ions were obtained a laser-produced plasma. A narrow bandwidth UV laser pulse was employed to selectively populate short-lived upper lifetime values evaluated from signals recorded by fast detection system. Transition probabilities for branching fractions calculated Cowan code experimental lifetimes. The...
Optical region spectra for a number of upper main sequence chemically peculiar (CP) stars have been observed to study singly and doubly ionized praseodymium neodymium lines. In order improve existing atomic data these elements, laboratory measurements carried out with the Lund VUV Fourier Transform Spectrometer (FTS). From wavelengths hyperfine structure (hfs) studied selected , lines astrophysical interest. Radiative life times some excited states determined aid laser spectroscopy at Laser...
view Abstract Citations (57) References (54) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS An Optical Region Elemental Abundance Analysis of the Chemically Peculiar HgMn Star chi LUPI Wahlgren, Glenn M. ; Adelman, Saul J. Robinson, Richard D. The optical spectrum chemically peculiar type binary star Lupi has been analyzed to determine atmospheric parameters and elemental abundances. Echelle spectra were obtained with 3.9 m Anglo-Australian telescope exploit...
The nova outburst of V407 Cyg in 2010 Mar. 10 was the first observed for this star but its close resemblance to well known symbiotic-like recurrent RS Oph suggests that it is also a member rare type Galactic novae. detected at $\gamma$-ray energies and explosion system. extensive multiwavelength coverage makes an ideal comparison with few other outbursts similar systems. We extend our previous analysis Mira expanding shock from detail time development photoionized wind, circumstellar medium,...
Boron abundances and isotope ratios in two early B stars have been measured by using the Hubble Space Telescope's Goddard High-Resolution Spectrograph (GHRS) order to observe III resonance doublet near 2066 Å. We also report new experimental theoretical results for wavelengths, shift, hyperfine structure of these boron lines. In HD 886 (γ Pegasi; B2 IV), 35299 (B1 V) abundance is about a factor 2 lower than that inferred from solar system meteorites. The 11B/10B ratio determined be 4.7,...
We report new laboratory spectroscopic analyses that have been conducted to acquire wavelength and oscillator strength data for lines of the Re II UV 1 multiplet. Wavelengths were determined a sub-milliangstrom accuracy hyperfine isotopic structure components from spectra obtained with Lund VUV Fourier Transform Spectrometer. An absolute atomic transition probability is reported 2275.253 Å, its upper level lifetime an experimentally branching fraction. The radiative z7Po2 was found be 4.47 ±...
Oscillator strengths for selected transitions of Sr II and Y III have been determined using ab initio multiconfiguration Hartree-Fock techniques. The importance including an accurate treatment the core-valence correlation is emphasized. results are used to determine abundances in chemically peculiar star χ Lupi from HST/GHRS Echelle spectra. Overabundances 2.09 dex 2.8 relative solar abundance derived, ionization imbalance +1.1 evident determinations II.