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(Abridged) We have observed CS and C17O lines, and 1.2 mm cont. emission towards a sample of 130 high-mass protostellar candidates with DEC<-30 deg. This is the first step of the southern extension of a project started more than a decade…

Astrophysics · Physics 2009-11-10 F. Fontani , M. T. Beltran , J. Brand , R. Cesaroni , L. Testi , S. Molinari , C. M. Walmsley

We present observations of the $^3P_1$-$^3P_0$ fine-structure line of atomic carbon using the ASTE 10 m sub-mm telescope towards RCW38, the youngest super star cluster in the Milky Way. The detected [CI] emission is compared with the CO $J$…

We derived the dust-to-HI ratio of the intermediate-velocity clouds (IVCs), the high-velocity clouds (HVCs), and the local HI gas, by carrying out a multiple-regression analysis of the 21cm HI emission combined with the sub-mm dust optical…

Astrophysics of Galaxies · Physics 2024-01-24 Takahiro Hayakawa , Yasuo Fukui

Neither HI nor CO emission can reveal a significant quantity of so-called dark gas in the interstellar medium (ISM). It is considered that CO-dark molecular gas (DMG), the molecular gas with no or weak CO emission, dominates dark gas. We…

Astrophysics of Galaxies · Physics 2016-09-14 Ningyu Tang , Di Li , Carl Heiles , Shen Wang , Zhichen Pan , Jun-Jie Wang

Spitzer and IRAS observations of the LMC suggest an excess of FIR emission with respect to the gas surface density traced by 12CO and HI 21 cm emission lines. This "FIR excess" is noticeable near molecular clouds in the LMC, and has usually…

We have obtained high resolution FUSE and HST/STIS echelle observations of the quasar PG 1116+215. The semi-continuous coverage of the ultraviolet spectrum over the wavelength range 916-2800 provides detections of Galactic and high velocity…

Astrophysics · Physics 2009-11-10 Rajib Ganguly , Kenneth R. Sembach , Todd M. Tripp , Blair D. Savage

We present J=1-0 and J=2-1 12CO maps of several star-forming regions in both the Large and the Small Magellanic Cloud, and briefly discuss their structure. Many of the detected molecular clouds are relatively isolated and quite small with…

Carbon monoxide (CO) is a poor tracer of H$_{2}$ in the diffuse interstellar medium (ISM), where most of the carbon is not incorporated into CO molecules unlike the situation at higher extinctions. We present a novel, indirect method to…

Astrophysics of Galaxies · Physics 2023-12-18 Raphael Skalidis , Paul F. Goldsmith , Philip F. Hopkins , Sam B. Ponnada

We present a search for infrared dust emission associated with the Leo cloud, a large intergalactic cloud in the M96 group. Mid-infrared and far-infrared images were obtained with IRAC and MIPS on the Spitzer Space Telescope. Our analysis…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 C. Bot , G. Helou , W. B. Latter , J. Puget , S. Schneider , Y. Terzian

We report the discovery of eleven high-velocity HI clouds at Galactic latitudes of 25-30 degrees, likely embedded in the Milky Way's nuclear wind. The clouds are detected with deep Green Bank Telescope 21 cm observations of a $3.2^\circ…

Astrophysics of Galaxies · Physics 2025-07-08 Rongmon Bordoloi , Andrew J. Fox , Felix J. Lockman

Using UV spectra obtained with FUSE, HST, and/or IUE, we determine interstellar column densities of 12CO, 13CO, and/or C_2 for ten Galactic sight lines with 0.37<E(B-V)<0.72. The N(CO)/N(H_2) ratio varies over a factor of 100 in this…

Astrophysics · Physics 2009-05-29 P. Sonnentrucker , D. E. Welty , J. A. Thorburn , D. G. York

We suggest that the high--velocity clouds (HVCs) are large clouds, with typical diameters of 25 kpc and containing 5e7 solar masses of neutral gas and 3e8 solar masses of dark matter, falling onto the Local Group; altogether the HVCs…

Astrophysics · Physics 2010-11-23 Leo Blitz , David N. Spergel , Peter J. Teuben , Dap Hartmann , W. Butler Burton

This letter presents a Nyquist-sampled, high-resolution [CI] 3P1-3P0 map of the -0.2 deg < l < 1.2 deg x -0.1 deg < b < 0 deg region in the Central Molecular Zone (CMZ) taken with the Atacama Submillimeter Telescope Experiment (ASTE) 10 m…

Astrophysics of Galaxies · Physics 2015-06-03 Kunihiko Tanaka , Tomoharu Oka , Shinji Matsumura , Makoto Nagai , Kazuhisa Kamegai

With new THz maps that cover an area of ~3.3x2.1 pc^2 we probe the spatial distribution and association of the ionized, neutral and molecular gas components in the M17 SW nebula. We used the dual band receiver GREAT on board the SOFIA…

Astrophysics of Galaxies · Physics 2015-06-04 J. P. Perez-Beaupuits , H. Wiesemeyer , V. Ossenkopf , J. Stutzki , R. Guesten , R. Simon , H. -W. Huebers , O. Ricken

To understand the impact of low metallicities on giant molecular cloud (GMC) structure, we compare far infrared dust emission, CO emission, and dynamics in the star-forming complex N83 in the Wing of the Small Magellanic Cloud. Dust…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-12 A. K. Leroy , A. Bolatto , C. Bot , C. W. Engelbracht , K. Gordon , F. P. Israel , M. Rubio , K. Sandstrom , S. Stanimirović

We present deep HI 21-cm and optical observations of the face-on spiral galaxy M 83 obtained as part of a project to search for high-velocity clouds (HVCs) in nearby galaxies. Anomalous-velocity neutral gas is detected toward M 83, with…

Astrophysics · Physics 2011-02-11 Eric D. Miller , Joel N. Bregman , Bart P. Wakker

Given the current and past star-formation in the Milky Way in combination with the limited gas supply, the re-fuelling of the reservoir of cool gas is an important aspect of Galactic astrophysics. The infall of \ion{H}{i} halo clouds can,…

Astrophysics of Galaxies · Physics 2015-01-07 Daniel Lenz , Jürgen Kerp , Lars Flöer , Benjamin Winkel , François Boulanger , Guilaine Lagache

(Abridged) We aim to determine the degrees of CO depletion, deuterium fractionation, and ionisation in a sample of seven massive clumps associated with IRDCs. The APEX telescope was used to observe the C17O(2-1), H13CO+(3-2), DCO+(3-2),…

Astrophysics of Galaxies · Physics 2015-05-30 Oskari Miettinen , Martin Hennemann , Hendrik Linz

Ten isolated compact high-velocity clouds (CHVCs) of the type cataloged by Braun & Burton (1999) have been imaged with the Arecibo telescope and were found to have a nested core/halo morphology. We argue that a combination of…

Astrophysics · Physics 2009-11-06 W. B. Burton , R. Braun , J. N. Chengalur

The Galactic Center regions $-6^\circ \le l \le 6^\circ$ and $-0.8^\circ \le b \le 0.87^\circ$ are surveyed with HCN J=1$-$0 line (88.6 GHz) on a 4$'$ grid with the 14 m telescope at the Taeduk Radio Astronomy Observatory. The data…

Astrophysics · Physics 2009-10-28 Chang Won Lee