Results 11 to 20 of about 1,250,237 (300)
Origins of the H, He I, and Ca II Line Emission in Classical T Tauri Stars [PDF]
Monthly Notices of the Royal Astronomical Society, 2010 We perform local excitation calculations to obtain line opacities and emissivity ratios and compare them with observed properties of H, He I, O I, Ca II, and Na I lines to determine the density, temperature, and photon ionization rate.
Fischer, William, Kwan, John
core +4 more sources
Stellar Inclination Angles from Be-star Hα Emission Line Profiles [PDF]
The Astrophysical Journal, 2020 We demonstrate that the angle between star's rotation axis and the observer's line-of-sight, usually called the inclination angle, can be reliably determined for Be stars via H$α$ emission-line profile fitting. We test our method on a sample of 11 Be stars with available long-baseline interferometric data from the Navy Precision Optical Interferometer~(
T. A. A. Sigut, A. K. Mahjour, C. Tycner
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Hα Emission Lines in High Redshift Quasars [PDF]
Symposium - International Astronomical Union, 1989 We present new data on the redshifts and Hα profiles of 18 medium to high redshift QSOs observed by us using the FIGS spectrometer at the Anglo-Australian Telescope facility and compare the data to that of the strong UV lines obtained in spectra taken at nearly the same time.
B.R. Espey +4 more
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Drivers of asymmetry in synthetic H
Monthly Notices of the Royal Astronomical Society, 2021 ABSTRACT We study the shapes of spatially integrated $\rm{H}\, \small {{I}}$ emission-line profiles of galaxies in the eagle simulation using three separate measures of the profile’s asymmetry. We show that the subset of eagle galaxies whose gas fractions and stellar masses are consistent with those in the xGASS survey also have similar $
Aditya Manuwal +4 more
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The Astrophysical Journal, 2023 The thermal history of the intergalactic medium is full of extremely useful data in the field of astrophysics and cosmology. In other words, by examining this environment in different redshifts, the effects of cosmology and astrophysics can be observed ...
S. Mobina Hosseini +3 more
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LINE EMISSION FROM RADIATION-PRESSURIZED H II REGIONS. I. INTERNAL STRUCTURE AND LINE RATIOS [PDF]
The Astrophysical Journal, 2013 8 pages, 4 figures, accepted for publication in ...
Yeh, Sherry C. C. +4 more
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Hα emission-line stars in molecular clouds [PDF]
Astronomy & Astrophysics, 2019 A deep objective-prism survey for Hα emission stars towards the Canis Major star-forming clouds was performed. A total of 398 Hα emitters were detected, 353 of which are new detections. There is a strong concentration of these Hα emitters towards the molecular clouds surrounding the CMa OB1 association, and it is likely that these stars are young ...
Pettersson, B., Reipurth, B.
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H2 and HI Emission Line Imaging of the Ring Nebula NGC 6720 [PDF]
Symposium - International Astronomical Union, 1988 We present infrared emission line images of the v = 1 → 0 S(1) transition of molecular hydrogen and Brγ recombination line of atomic hydrogen which cover the entire extent of NGC 6720, the Ring Nebula. The maps presented here are the highest angular resolution images of these transitions yet produced for this object, and have very low relative ...
M. A. Greenhouse +2 more
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J-PLUS: Measuring Hα emission line fluxes in the nearby universe [PDF]
Astronomy & Astrophysics, 2019 In this paper we aim to validate a methodology designed to obtain Hα emission line fluxes from J-PLUS photometric data. J-PLUS is a multi narrow-band filter survey carried out with the 2 deg2 field of view T80Cam camera, mounted on the JAST/T80 telescope in the OAJ, Teruel, Spain.
Logroño-García, R. +31 more
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The Astronomical Journal, 2023 We report VLA B-configuration observations of the H i 21 cm line on the close disk galaxy pair NGC 5595 and NGC 5597. At the angular resolution of the observations, ∼7.″1 × 4.″2, while most of the H i 21 cm in NGC 5595 and NGC 5597 has the same extent as
J. Antonio Garcia-Barreto +1 more
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