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相关论文: Probing UV-Sensitive Pathways for CN and HCN Forma…

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We analyze the ultraviolet (UV) emission line and continuum properties of five low-redshift active galactic nuclei (four luminous quasars: PKS~0405$-$123, H1821+643, PG~0953+414, and 3C273, and one bright Seyfert 1 galaxy: Mrk~205). The HST…

Observations of Carbon bearing species are among the most important diagnostic probes of ongoing star formation. CO is a surrogate for H$_2$ and is found in the vicinity of star formation sites. There, [CI] emission is thought to outline…

天体物理学 · 物理学 2017-01-18 H. Jakob , R. Simon , C. Kramer , B. Mookerjea , N. Schneider , S. Bontemps , J. Stutzki

A survey of mid-IR gas-phase emission lines of H2, H2O and various atoms toward a sample of 43 embedded low-mass young stars in nearby star-forming regions is presented. The sources are selected from the Spitzer "Cores to Disks" (c2d)…

星系天体物理 · 物理学 2015-05-19 Fred Lahuis , Ewine F. van Dishoeck , Jes K. Jørgensen , Geoffrey A. Blake , Neal J. Evans

The young and well-studied planetary nebula NGC 7027 harbors significant molecular gas that is irradiated by luminous, point-like UV (central star) and diffuse (shocked nebular) X-ray emission. This nebula represents an excellent subject to…

As a step towards clarifying the ionization mechanism of LINERs, we have used the Hubble Space Telescope Faint Object Spectrograph to obtain an ultraviolet spectrum of the nucleus of NGC 6500. Compared with more luminous Seyfert nuclei, the…

天体物理学 · 物理学 2009-10-30 A. J. Barth , G. A. Reichert , L. C. Ho , J. C. Shields , A. V. Filippenko , E. M. Puchnarewicz

With the launch of JWST and the upcoming installation of extremely large telescopes, the first galaxies in our Universe will finally be revealed. Their light will be dominated by massive stars, which peak in in the ultra-violet (UV) part of…

星系天体物理 · 物理学 2020-05-15 Jorick S. Vink

Measurements of the UV-continuum slopes provide valuable information on the physical properties of galaxies forming in the early universe, probing the dust reddening, age, metal content, and even the escape fraction. While constraints on…

In this work we study the influence of the UV radiation field of a massive star on the evolution of a disklike mass of gas and dust around a nearby star. This system has similarities with the Orion proplyds. We study disks with different…

星系天体物理 · 物理学 2011-02-16 M. J. Vasconcelos , A. H. Cerqueira , A. C. Raga

We present measurements of diffuse ultraviolet emission in the dwarf irregular galaxy Holmberg II obtained with the UltraViolet Imaging Telescope (UVIT) onboard AstroSat. With a spatial resolution of 1.2 to 1.6 arcsec, these are the highest…

We present a far-ultraviolet (FUV) spectral atlas consisting of spectra of 91 pre-main sequence stars. Most stars in this sample were observed with the Space Telescope Imaging Spectrograph (STIS) and Advanced Camera for Surveys (ACS) on the…

Stellar ultraviolet (UV) emission serves as a crucial indicator for estimating magnetic activity and evaluating the habitability of exoplanets orbiting stars. In this paper, we present a straightforward method to derive stellar photospheric…

太阳与恒星天体物理 · 物理学 2024-10-16 Song Wang , Xue Li , Henggeng Han , Jifeng Liu

Aims: The two stable isotopes of nitrogen, 14N and 15N, exhibit a range of abundance ratios both inside and outside the solar system. The elemental ratio in the solar neighborhood is 440. Recent ALMA observations showed HCN/HC15N ratios…

太阳与恒星天体物理 · 物理学 2018-07-18 Ruud Visser , Simon Bruderer , Paolo Cazzoletti , Stefano Facchini , Alan N. Heays , Ewine F. van Dishoeck

The extended ultraviolet (XUV) disk galaxies are one of the most interesting objects studied in the last few years. The UV emission, revealed by GALEX, extends well beyond the optical disk, after the drop of H$\alpha$ emission, the usual…

星系天体物理 · 物理学 2019-03-06 Isadora C. Bicalho , Francoise Combes , Monica Rubio , Celia Verdugo , Philippe Salome

In our Galaxy, star formation occurs in a variety of environments, with a large fraction of stars formed in clusters hosting massive stars. OB stars have an important feedback on the evolution of protoplanetary disks around nearby young…

Far-ultraviolet (FUV) radiation plays an important role in determining chemical abundances in protoplanetary disks. HI Lyman alpha is suspected to be the dominant component of the FUV emission from Classical T Tauri Stars (CTTSs), but is…

High energy X-ray and ultraviolet (UV) radiation from young stars impacts planetary atmospheric chemistry and mass loss. The active $\sim 22$ Myr M dwarf AU Mic hosts two exoplanets orbiting interior to its debris disk. Therefore, this…

Classical T Tauri stars (CTTS) are young (< 10 Myr), cool stars that actively accrete matter from a disk. They show strong, broad and asymmetric, atomic FUV emission lines. Neither the width, nor the line profile is understood. Likely,…

太阳与恒星天体物理 · 物理学 2014-08-18 H. M. Günther , N. S. Brickhouse , A. K. Dupree , S. J. Wolk , P. C. Schneider , G. J. M. Luna

Young solar-type stars grow through the accretion of material from the circumstellar disk during pre-main sequence (PMS) evolution. The ultraviolet radiation generated in this process plays a key role in the chemistry and evolution of young…

太阳与恒星天体物理 · 物理学 2016-02-17 Ana I. Gomez de Castro , Robert O. P. Loyd , Kevin France , Alexey Sytov , Dmitry Bisikalo

In these proceedings, we summarize recent results from our "SINS" VLT/SINFONI integral-field survey, focusing on the 52 detected UV/optically-selected star-forming galaxies at z~2. Our H-alpha emission-line imaging and kinematic data of…

{CircumStellar Envelopes (CSEs) of stars are complex chemical objects for which theoretical models encounter difficulties in elaborating a comprehensive overview of the occurring chemical processes. Along with photodissociation, ion-neutral…

太阳与恒星天体物理 · 物理学 2022-12-08 Jérémy Bourgalais , David V. Bekaert , Aurore Bacmann , Bernard Marty , Nathalie Carrasco