Physical Properties of Diffuse H° Gas in the Galaxy

2007 ◽  
Vol 23 ◽  
pp. 55-72
Author(s):  
T.H. Troland
Keyword(s):  
Physical Properties ◽  
The Galaxy

scholarly journals The properties of early-type stars in the Magellanic Clouds

2008 ◽  
Vol 4 (S256) ◽  
pp. 325-336
Author(s):  
Christopher J. Evans
Keyword(s):  
Physical Properties ◽  
Mass Loss ◽  
Temperature Scale ◽  
Massive Stars ◽  
Magellanic Clouds ◽  
Early Type ◽  
The Past ◽  
The Galaxy ◽  
Stellar Temperature ◽  
Early Type Stars

AbstractThe past decade has witnessed impressive progress in our understanding of the physical properties of massive stars in the Magellanic Clouds, and how they compare to their cousins in the Galaxy. I summarise new results in this field, including evidence for reduced mass-loss rates and faster stellar rotational velocities in the Clouds, and their present-day compositions. I also discuss the stellar temperature scale, emphasizing its dependence on metallicity across the entire upper-part of the Hertzsprung-Russell diagram.

scholarly journals Ionised gas structure of 100 kpc in an over-dense region of the galaxy group COSMOS-Gr30 at z ~ 0.7

2018 ◽  
Vol 609 ◽  
pp. A40 ◽  
Author(s):  
B. Epinat ◽  
T. Contini ◽  
H. Finley ◽  
L. A. Boogaard ◽  
A. Guérou ◽  
...  
Keyword(s):  
Physical Properties ◽  
High Velocity ◽  
Active Galactic Nucleus ◽  
Dense Region ◽  
Tidal Forces ◽  
Shock Models ◽  
The Galaxy ◽  
Group Members ◽  
Low Mass ◽  
Massive Galaxy

We report the discovery of a 104 kpc2 gaseous structure detected in [O ii]λλ3727, 3729 in an over-dense region of the COSMOS-Gr30 galaxy group at z ~ 0.725 with deep MUSE Guaranteed Time Observations. We estimate the total amount of diffuse ionised gas to be of the order of (~5 ± 3) × 1010 M⊙ and explore its physical properties to understand its origin and the source(s) of the ionisation. The MUSE data allow the identification of a dozen group members that are embedded in this structure through emission and absorption lines. We extracted spectra from small apertures defined for both the diffuse ionised gas and the galaxies. We investigated the kinematics and ionisation properties of the various galaxies and extended gas regions through line diagnostics (R23, O32, and [O iii]/Hβ) that are available within the MUSE wavelength range. We compared these diagnostics to photo-ionisation models and shock models. The structure is divided into two kinematically distinct sub-structures. The most extended sub-structure of ionised gas is likely rotating around a massive galaxy and displays filamentary patterns that link some galaxies. The second sub-structure links another massive galaxy that hosts an active galactic nucleus (AGN) to a low-mass galaxy, but it also extends orthogonally to the AGN host disc over ~ 35 kpc. This extent is likely ionised by the AGN itself. The location of small diffuse regions in the R23 vs. O32 diagram is compatible with photo-ionisation. However, the location of three of these regions in this diagram (low O32, high R23) can also be explained by shocks, which is supported by their high velocity dispersions. One edge-on galaxy shares the same properties and may be a source of shocks. Regardless of the hypothesis, the extended gas seems to be non-primordial. We favour a scenario where the gas has been extracted from galaxies by tidal forces and AGN triggered by interactions between at least the two sub-structures.

scholarly journals Gaia: A Stereoscopic Census of Our Galaxy

2009 ◽  
Vol 5 (H15) ◽  
pp. 816-816
Author(s):  
T. Prusti
Keyword(s):  
Physical Properties ◽  
Elemental Composition ◽  
Observational Data ◽  
Evolutionary History ◽  
Three Dimensional ◽  
Subsequent Evolution ◽  
The Galaxy ◽  
History Of ◽  
Space Astrometry ◽  
Modern Astronomy

AbstractGaia is a space astrometry mission, a broad survey project following the measurement and operational principles of Hipparcos. It will help solving one of the most difficult yet deeply fundamental challenges in modern astronomy: to create an extraordinarily precise three-dimensional map of about one billion stars throughout our Galaxy and beyond. In the process, it will map their three-dimensional motions, which encode the origin and subsequent evolution of the Galaxy. Through comprehensive photometric and spectroscopic classification, it will provide the detailed physical properties of each star observed: characterising their luminosity, temperature, gravity, and elemental composition. This massive stellar census will provide the basic observational data to tackle an enormous range of important problems related to the origin, structure, and evolutionary history of our Galaxy.

scholarly journals The prevalence and physical properties of extremely low-luminosity galaxies in the early universe

2019 ◽  
Vol 15 (S352) ◽  
pp. 19-19
Author(s):  
Rychard Bouwens
Keyword(s):  
Physical Properties ◽  
Galaxy Clusters ◽  
Early Universe ◽  
Gravitational Lensing ◽  
Stellar Population ◽  
Space Telescope ◽  
James Webb Space Telescope ◽  
Luminosity Functions ◽  
The Galaxy ◽  
Stellar Masses

AbstractGravitational lensing from galaxy clusters has great potential for deriving the prevalence and physical properties of ultra-faint galaxies at early times, with recent very impressive results from the Hubble Frontier Fields program. Important issues in deriving the most accurate results are accurate constraints on source sizes and a robust treatment of uncertainties in the magnification models. Using > 3300 z = 2 – 10 galaxies behind the 6 Hubble Frontier Fields clusters and a forwards modeling approach, I describe the efforts of my collaborators and me to map out the galaxy luminosity functions at ∼ − 13 mag from z ∼ 9 to z ∼ 2, i.e, a factor of 1000 below Lå and to the typical luminosity of galaxies suspected to drive cosmic reionization. Additionally, I discuss the constraints we can obtain on the properties of faint sources, in particular their stellar masses, mass-to-light ratios, colors, and stellar population ages. I conclude with a prospective on using cluster lenses to study the distant universe with the James Webb Space Telescope.

Physical properties of neutral gas in M31 and the Galaxy

1992 ◽  
Vol 386 ◽  
pp. 120 ◽  
Author(s):  
Robert Braun ◽  
Rene A. M. Walterbos
Keyword(s):  
Physical Properties ◽  
Neutral Gas ◽  
The Galaxy

scholarly journals The Galaxy and its stellar halo - insights from a hybrid cosmological approach

2008 ◽  
Vol 4 (S254) ◽  
pp. 423-428
Author(s):  
Gabriella De Lucia ◽  
Amina Helmi
Keyword(s):  
High Resolution ◽  
Physical Properties ◽  
Milky Way ◽  
Dynamical Friction ◽  
Milky Way Galaxy ◽  
The Galaxy ◽  
Stellar Halo ◽  
Good Agreement ◽  
Milky Way Halo

AbstractWe use a series of high-resolution N-body simulations of a ‘Milky-Way’ halo, coupled to semi-analytic techniques, to study the formation of our own Galaxy and of its stellar halo. Our model Milky Way galaxy is a relatively young system whose physical properties are in quite good agreement with observational determinations. In our model, the stellar halo is mainly formed from a few massive satellites accreted early on during the galaxy's lifetime. The stars in the halo do not exhibit any metallicity gradient, but higher metallicity stars are more centrally concentrated than stars with lower abundances. This is due to the fact that the most massive satellites contributing to the stellar halo are also more metal rich, and dynamical friction drags them closer to the inner regions of the host halo.

scholarly journals Properties of the Environment of Galaxies in Clusters of Galaxies CL 0024+1654 and RX J0152.7−1357

2021 ◽  
Vol 53 (3) ◽  
pp. 428-250
Author(s):  
Premana Wardayanti Premadi ◽  
Dading Hadi Nugroho ◽  
Anton Timur Jaelani
Keyword(s):  
Physical Properties ◽  
Galaxy Evolution ◽  
Gravitational Lensing ◽  
Mass Density ◽  
Formation Rate ◽  
Close Relation ◽  
Optical Data ◽  
X Ray ◽  
Physical Description ◽  
The Galaxy

We report the results of combined analyses of X-ray and optical data of two galaxy clusters, CL 0024+1654 and RX J0152.7−1357 at redshift z = 0.395 and z = 0.830, respectively, offering a holistic physical description of the two clusters. Our X-ray analysis yielded temperature and density profiles of the gas in the intra-cluster medium (ICM). Using optical photometric and spectroscopic data, complemented with mass distribution from a gravitational lensing study, we investigated any possible correlation between the physical properties of the galaxy members, i.e. their color, morphology, and star formation rate (SFR), and their environments. We quantified the properties of the environment around each galaxy by galaxy number density, ICM temperature, and mass density. Although our results show that the two clusters exhibit a weaker correlation compared to relaxed clusters, it still confirms the significant effect of the ICM on the SFR in the galaxies. The close relation between the physical properties of galaxies and the condition of their immediate environment found in this work indicates the locality of galaxy evolution, even within a larger bound system such as a cluster. Various physical mechanisms are suggested to explain the relation between the properties of galaxies and their environment.

Physical Properties of a Gaseous Substratum in the Galaxy

1929 ◽  
Vol 69 ◽  
pp. 7 ◽  
Author(s):  
B. P. Gerasimovic ◽  
O. Struve
Keyword(s):  
Physical Properties ◽  
The Galaxy

scholarly journals Large-Scale Molecular Gas Survey in 12CO, 13CO and C18O (J = 2–1) with the Osaka 1.85m mm-submm Telescope

2015 ◽  
Vol 11 (S315) ◽  
Author(s):  
Toshikazu Onishi ◽  
Atsushi Nishimura ◽  
Kazuki Tokuda ◽  
Ryohei Harada ◽  
Kazuhito Dobashi ◽  
...  
Keyword(s):  
Physical Properties ◽  
Molecular Clouds ◽  
Large Scale ◽  
Molecular Gas ◽  
Beam Size ◽  
Radio Observatory ◽  
Target Frequency ◽  
Scientific Goal ◽  
The Galaxy ◽  
Scientific Results

AbstractWe have developed a new mm-submm telescope with a diameter of 1.85 m (hereafter, Osaka 1.85-m telescope) installed at the Nobeyama Radio Observatory. The scientific goal is to precisely reveal physical properties of molecular clouds in the Galaxy by obtaining a large-scale distribution of molecular gas, which also can be compared with large-scale observations in various wavelengths. The target frequency is ~230 GHz; simultaneous observations in J = 2–1 lines of 12CO, 13CO and C18O are achieved with a beam size (HPBW) of 2.7 arcmin. Here we present the progress of observations and the scientific results obtained by Osaka 1.85-m telescope. We note that these J = 2–1 data of the Galactic molecular clouds will be precious for the comparison with those of extra-galactic ones that will be obtained with the ALMA with the comparable spatial resolutions.

Investigating the early phase of the galaxy evolution through high-z damped Lyα absorption systems

2019 ◽  
Vol 15 (S341) ◽  
pp. 294-296
Author(s):  
Kazuyuki Ogura ◽  
Tohru Nagao ◽  
Masatoshi Imanishi ◽  
Nobunari Kashikawa ◽  
Yoshiaki Taniguchi ◽  
...  
Keyword(s):  
Physical Properties ◽  
Galaxy Evolution ◽  
Early Phase ◽  
Luminosity Function ◽  
The Other ◽  
Other Hand ◽  
The Galaxy

AbstractWe present the physical properties of Lyα emitters (LAEs) in a “DLA-concentrated regions” where there are 3 or more DLA within (50 Mpc)3 cubic box. We observed LAEs in a DLA-concentrated region at z = 2.3, the J1230+34 field, with Subaru/Suprime-Cam. In the 50 Mpc scale, we found no deferences in properties of LAEs such as Lyα luminosity function in the DLA-concentrated region compared to other fields at similar redshift. On the other hand, we found a ∼10 Mpc scale LAE overdensity around a strong DLA with NHI = 1021.08 cm−2.

Sign in / Sign up

Export Citation Format

Share Document