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Related papers: The First RELHIC? Cloud-9 is a Starless Gas Cloud

200 papers

We discovered two small high-velocity compact clouds (HVCCs) in HCN $J=4-3$ and $J=3-2$ maps of the central 20 pc of our Galaxy. Both HVCCs have broad velocity widths ($\Delta V \gtrsim 40$ km s$^{-1}$) and compact sizes ($d\sim 1$ pc), and…

Astrophysics of Galaxies · Physics 2017-07-19 Shunya Takekawa , Tomoharu Oka , Yuhei Iwata , Sekito Tokuyama , Mariko Nomura

Our view of the high velocity cloud (HVC) system is changing dramatically with new observations from the Far Ultraviolet Spectroscopic Explorer mission and the Space Telescope Imaging Spectrograph onboard the Hubble Space Telescope. In…

Astrophysics · Physics 2007-05-23 Kenneth R. Sembach

We present our investigation of HI-rich 'Dark' galaxiEs in Simulations (HIDES), specifically using the Hestia and Auriga simulations in this work. We select galaxies that are faint ($M_g > -10$) and contain sufficient HI ($M_\mathrm{HI} >…

Astrophysics of Galaxies · Physics 2025-11-24 Haonan Zheng , Fangzhou Jiang , Shihong Liao , Noam I. Libeskind

We report the discovery of a large HI cloud in the central regions of the Virgo cluster. It is 110 x 25 kpc in size and contains 3.4 x 10^8 Msol of HI. The morphology and kinematics of this cloud strongly suggest that it consists of HI…

Astrophysics · Physics 2009-11-11 Tom Oosterloo , Jacqueline van Gorkom

With IRAM-30m/HERA, we have detected CO(2-1) gas complexes within 30 arcsec (~100 pc) from the center of M31 amounting to a minimum total mass of 4.2 x 10^4 Msol (one third of the positions are detected). Averaging the whole HERA field, we…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 A. -L. Melchior , F. Combes

The Small Magellanic Cloud (SMC) is the second-largest satellite galaxy of the Milky Way and is only 60 kpc away. As a nearby, massive, and dense object with relatively low astrophysical backgrounds, it is a natural target for dark matter…

We present the discovery of a very faint stellar system, SMASH 1, that is potentially a satellite of the Large Magellanic Cloud. Found within the Survey of the MAgellanic Stellar History (SMASH), SMASH 1 is a compact ($r_h =…

Ghostly stellar haloes are extended haloes of stars composed solely of debris of pre-reionization fossil galaxies and should exist in dwarf galaxies with total masses $<10^{10}$ M$_\odot$. Fossil galaxies are even smaller mass dwarf…

Astrophysics of Galaxies · Physics 2022-09-07 Massimo Ricotti , Emil Polisensky , Emily Cleland

We present 21 cm observations of a 10 $\times$ 2 degree region in the Virgo cluster, obtained as part of the Arecibo Galaxy Environment Survey. 289 sources are detected over the full redshift range (-2,000 $<$ $v$$_{hel}$ $<$ + 20,000 km/s)…

Astrophysics of Galaxies · Physics 2015-06-04 R. Taylor , J. I. Davies , R. Auld , R. F. Minchin

We report an accurate distance of d = 10+/-2.5kpc to the high-velocity cloud Complex C. Using high signal-to-noise Keck/HIRES spectra of two horizontal-branch stars, we have detected CaII K absorption lines from the cloud. Significant…

Astrophysics · Physics 2009-11-13 C. Thom , J. E. G. Peek , M. E. Putman , Carl Heiles , K. M. G. Peek , R. Wilhelm

High-velocity clouds (HVC), fast-moving ionized and neutral gas clouds found at high galactic latitudes, may play an important role in the evolution of the Milky Way. The extent of this role depends sensitively on their distances and total…

Astrophysics of Galaxies · Physics 2015-06-04 N. Lehner , J. C. Howk , C. Thom , A. J. Fox , J. Tumlinson , T. M. Tripp , J. D. Meiring

Context: Infrared dark clouds are the coldest and densest portions of giant molecular clouds. The most massive ones represent some of the most likely birthplaces for the next generation of massive stars in the Milky Way. Because a strong…

Astrophysics of Galaxies · Physics 2015-08-19 A. Giannetti , F. Wyrowski , S. Leurini , J. Urquhart , T. Csengeri , K. M. Menten , L. Bronfman , F. F. S. van der Tak

Cold gas evolution ties the formation of dark matter halos to the star formation history of the universe. A primary component of cold gas, neutral atomic hydrogen (HI), can be traced by its 21-cm emission line. However, the faintness of…

Astrophysics of Galaxies · Physics 2024-07-12 Tariq Blecher , Roger Deane , Danail Obreschkow , Ian Heywood

In order to understand galaxy growth evolution, it is critical to constrain the evolution of its building block: gas. Mostly comprised by Hydrogen in its neutral (HI) and molecular (H2) phases, the latter is the one mostly directly…

Astrophysics of Galaxies · Physics 2024-02-12 Hugo Messias , Andrea Guerrero , Neil Nagar , Jack Regueiro , Violette Impellizzeri , Gustavo Orellana , Miguel Vioque

High-velocity clouds (HVCs) are interstellar gas clouds whose velocities are incompatible with Galactic rotation. Since the first discovery of HVCs in 1963, their origins have been debated for decades but are still not settled down, because…

Astrophysics of Galaxies · Physics 2025-06-19 Yu-Ting Wang , Chao Liu , Zhi-Yu Zhang

We report the detection of a peculiar molecular cloud, CO 0.02-0.02, lying about 5' Galactic-east from the center of the Galaxy. (12)CO images taken with NRO 45 m telescope showed that it is relatively compact (about 3x4 pc^2) as well as…

Astrophysics · Physics 2009-10-31 T. Oka , G. J. White , T. Hasegawa , F. Sato , M. Tsuboi , A. Miyazaki

The Medusa (NGC 4194) is a well-studied nearby galaxy with the disturbed appearance of a merger and evidence for ongoing star formation. In order to test whether it could be the result of an interaction between a gas-rich disk-like galaxy…

Astrophysics · Physics 2009-11-13 E. Manthey , S. Huettemeister , S. Aalto , C. Horellou , P. Bjerkeli

We report the discovery of a new, low luminosity star cluster in the outer halo of the Milky Way. High quality $gr$ photometry is presented, from which a color-magnitude diagram is constructed, and estimates of age, [Fe/H], [$\alpha$/Fe],…

Astrophysics of Galaxies · Physics 2015-06-23 Dongwon Kim , Helmut Jerjen , Antonino P. Milone , Dougal Mackey , Gary S. Da Costa