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To characterize the initial conditions for intermediate- to high-mass star formation, we observed two Infrared Dark Clouds (IRDCs) that remain absorption features up to 70mum wavelength, with the PdBI in the 3.23mm dust continuum as well as…

太阳与恒星天体物理 · 物理学 2015-05-13 Henrik Beuther , Thomas Henning

One of the main problems in astrochemistry is determining the amount of sulfur in volatiles and refractories in the interstellar medium. The detection of the main sulfur reservoirs (icy H$_2$S and atomic gas) has been challenging, and…

Emission from the molecular ion H$_3^+$ is a powerful diagnostic of the upper atmosphere of Jupiter, Saturn, and Uranus, but it remains undetected at Neptune. In search of this emission, we present near-infrared spectral observations of…

地球与行星天体物理 · 物理学 2017-11-28 H. Melin , L. N. Fletcher , T. S. Stallard , R. E. Johnson , J. O'Donoghue , L. Moore , P. T. Donnelly

Intermediate-mass (IM) protostars provide a bridge between the low- and high-mass protostars. Despite their relevance, little is known about their chemical diversity. We want to investigate the molecular richness towards the envelope of IM…

太阳与恒星天体物理 · 物理学 2019-09-27 J. Ospina Zamudio , B. Lefloch , C. Ceccarelli , C. Kahane , C. Favre , A. López-Sepulcre , M. Montarges

We present an initial overview of the filamentary structure in the Orion A molecular cloud utilizing a high angular and velocity resolution C$^{18}$O(1-0) emission map that was recently produced as part of the CARMA-NRO Orion Survey. The…

We present 8--13 micron low resolution spectra (R~100) of 8 low-mass protostellar objects ("proplyds") in the Orion Nebula using the Long Wavelength Spectrometer (LWS) at the W. M. Keck Observatory. All but one of the sources in our sample…

天体物理学 · 物理学 2009-11-11 R. Y. Shuping , Marc Kassis , Mark Morris , Nathan Smith , John Bally

We present near-IR (1.1-2.4 micron) position-position-velocity cubes of the 500-year-old Orion BN/KL explosive outflow with spatial resolution 1" and spectral resolution 86 km/s. We construct integrated intensity maps free of continuum…

星系天体物理 · 物理学 2016-06-08 Allison Youngblood , Adam Ginsburg , John Bally

We report results from a FUSE survey of interstellar molecular hydrogen (H2) in the Galactic disk toward 139 O-type and early B-type stars at Galactic latitudes $|b| < 10^{\circ}$, with updated photometric and parallax distances. The H2…

星系天体物理 · 物理学 2021-04-21 J. Michael Shull , Charles W. Danforth , Katherine L. Anderson

A new interstellar molecule, CH$_3$NCO (methyl isocyanate), has been detected using the 12 m telescope of the Arizona Radio Observatory (ARO). CH$_3$NCO was identified in spectra covering 48 GHz (68-116 GHz) in the 3 mm segment of a…

太阳与恒星天体物理 · 物理学 2015-10-14 DeWayne T. Halfen , Vadim V. Ilyushin , Lucy M. Ziurys

We have mapped six molecular cloud cores in the Orion A giant molecular cloud (GMC), whose kinetic temperatures range from 10 to 30 K, in CCS and N2H+ with Nobeyama 45 m radio telescope to study their chemical characteristics. We identified…

The low column density gas at the outskirts of galaxies as traced by the 21 cm hydrogen line emission (HI) represents the interface between galaxies and the intergalactic medium, i.e., where galaxies are believed to get their supply of gas…

星系天体物理 · 物理学 2018-05-23 Roger Ianjamasimanana , Fabian Walter , W. J. G. de Blok , George H. Heald , Elias Brinks

NGC 7129 FIRS 2 (hereafter FIRS 2) is an intermediate-mass (2 to 8 Msun) protostar located at a distance of 1250 pc. High spatial resolution observations are required to resolve the hot core at its center. We present a molecular survey from…

太阳与恒星天体物理 · 物理学 2014-09-05 A. Fuente , J. Cernicharo , P. Caselli , C. McCoey , D. Johnstone , M. Fich , T. van Kempen , Aina Palau , U. A. Yildiz , B. Tercero , A. López

W51-IRS2 is known to be one of the most prolific sources of interstellar ammonia (NH$_3$) maser lines. So far, however, many of these inversion lines have rarely been studied. Here we report spectrally resolved line profiles for the…

星系天体物理 · 物理学 2025-08-20 E. Alkhuja , C. Henkel , Y. T. Yan , B. Winkel , Y. Gong , G. Wu , T. L. Wilson , A. Wootten , A. Malawi

Far-infrared continuum data from the {\it COBE}/{\it DIRBE} instrument were combined with Nagoya 4-m $\cOone$ spectral line data to infer the multiparsec-scale physical conditions in the Orion$ $A and B molecular clouds, using…

天体物理学 · 物理学 2008-11-26 W. F. Wall

We report interferometric measurements of [NII] 205 um fine-structure line emission from a representative sample of three galaxies at z=5-6 using the Atacama Large (sub)Millimeter Array (ALMA). These galaxies were previously detected in…

Today, the majority of the cosmic baryons in the Universe are not observed directly, leading to an issue of "missing baryons" at low redshift. Cosmological hydrodynamical simulations have indicated that a significant portion of them will be…

宇宙学与河外天体物理 · 物理学 2020-10-07 A. Fresco , C. Péroux , A. Merloni , A. Hamanowicz , R. Szakacs

Gas-phase hydroxylamine (NH$_2$OH) has recently been detected within dense clouds in the interstellar medium. However, it is also likely present within interstellar ices, as well as on the icy surfaces of outer Solar System bodies, where it…

We present an analysis of interstellar absorption along the line of sight to the nearby white dwarf star HZ43A. The distance to this star is 68+/-13 pc, and the line of sight extends toward the north Galactic pole. Column densities of OI,…

Interstellar chemistry in low metallicity environments is crucial to understand chemical processes in the past metal-poor universe. Recent studies of interstellar molecules in nearby low-metallicity galaxies have suggested that the…

星系天体物理 · 物理学 2021-12-08 Takashi Shimonishi , Natsuko Izumi , Kenji Furuya , Chikako Yasui

The advent of 8--10 meter class telescopes enables direct measurement of the chemical properties in the ionized gas of cosmologically--distant galaxies with the same nebular analysis techniques used in local H II regions. We show that…

天体物理学 · 物理学 2009-10-31 Henry A. Kobulnicky , Robert C. Kennicutt , James L. Pizagno
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