scholarly journals Observational Evidence for a Thick Disk of Dark Molecular Gas in the Outer Galaxy

2021 ◽  
Vol 914 (1) ◽  
pp. 72
Author(s):  
Michael P. Busch ◽  
Philip D. Engelke ◽  
Ronald J. Allen ◽  
David E. Hogg
Keyword(s):  
Observational Evidence ◽  
Thick Disk ◽  
Molecular Gas

scholarly journals A VLBI Study of H2O Maser Spots Associated with a Molecular Outflow ρ Oph-East

1994 ◽  
Vol 140 ◽  
pp. 60-61
Author(s):  
Takahiro Iwata ◽  
Hiroshi Takaba ◽  
Kin-Ya Matsumoto ◽  
Seiji Kameno ◽  
Noriyuki Kawaguchi
Keyword(s):  
Molecular Cloud ◽  
Observational Evidence ◽  
Molecular Gas ◽  
Mass Star ◽  
Dynamical Interaction ◽  
Star Forming ◽  
Star Forming Regions ◽  
Molecular Outflow ◽  
Low Mass ◽  
A Site

A molecular outflow is one of the most conspicuous active phenomena associated with protostars, and the kinetic energy of its outflowing mass is as large as that of random motions of ambient molecular cloud, which suggests that outflow has dynamically influence on ambient molecular gas. Possible observational evidence which suggests the existence of dynamical interaction between molecular outflow and ambient molecular cloud has been detected in several star forming regions (Fukui et al. 1986; Iwata et al. 1988). Recent detections of H2O maser emission associated with low-mass protostars (e.g. Comoretto et al. 1990) also suggest that there still exist active phenomena in the low-mass star forming regions.Molecular outflow ρ Oph-East, discovered toward a low-mass protostar IRAS 16293-2422 (Fukui et al. 1986), has been known as a site of dynamical interaction between molecular outflowing gas and ambient molecular cloud by CO and NH3 observation (Mizuno et al. 1990). Existence of several strong H2O maser spots (Wilking & Claussen 1987; Wotten 1989; Terebey et al. 1992) also suggests that active phenomena are occurring in this region. In this paper, we report our result of H2O maser observation for molecular outflow ρ Oph-East with milli-arcsecond resolution by VLBI.

scholarly journals The Canis Major Dwarf Galaxy

2004 ◽  
Vol 21 (4) ◽  
pp. 371-374
Author(s):  
Geraint F. Lewis ◽  
Rodrigo A. Ibata ◽  
Michael J. Irwin ◽  
Nicolas F. Martin ◽  
Michele Bellazzini ◽  
...  
Keyword(s):  
Building Block ◽  
Milky Way ◽  
Galactic Halo ◽  
Galactic Plane ◽  
Dwarf Galaxy ◽  
Observational Evidence ◽  
Thick Disk ◽  
Equatorial Orbit ◽  
Satellite Galaxy

AbstractRecent observational evidence suggests that the Sagittarius dwarf galaxy represents the only major ongoing accretion event in the Galactic halo, accounting for the majority of stellar debris identified there. This paper summarises the recent discovery of another potential Milky Way accretion event, the Canis Major dwarf galaxy. This dwarf satellite galaxy is found to lie just below the Galactic plane and appears to be on an equatorial orbit. Unlike Sagittarius, which is contributing to the Galactic halo, the location and eventual demise of Canis Major suggests that it represents a building block of the thick disk.

scholarly journals THE PLATEAU DE BURE + 30 m ARCSECOND WHIRLPOOL SURVEY REVEALS A THICK DISK OF DIFFUSE MOLECULAR GAS IN THE M51 GALAXY

2013 ◽  
Vol 779 (1) ◽  
pp. 43 ◽  
Author(s):  
Jérôme Pety ◽  
Eva Schinnerer ◽  
Adam K. Leroy ◽  
Annie Hughes ◽  
Sharon E. Meidt ◽  
...  
Keyword(s):  
Thick Disk ◽  
Molecular Gas

Gas in galactic halos

2012 ◽  
Vol 10 (H16) ◽  
pp. 596-597
Author(s):  
Ralf-Jürgen Dettmar
Keyword(s):  
Star Formation ◽  
Interstellar Medium ◽  
Observational Evidence ◽  
Molecular Gas ◽  
Galactic Halos ◽  
Feedback Mechanisms ◽  
X Ray

AbstractThe interstellar medium in galactic halos is described as a consequence of feedback mechanisms from processes related to star-formation in the disk. The presence of gas in galactic halos is also expected due to accretion of gas from the circumgalactic environment. The observational evidence for gas in galactic halos - from the hot X-ray emitting coronal phase to cool molecular gas and dust - is reviewed and discussed in the context of current models of the ISM and the “infall vs. outflow“ debate.

scholarly journals OBSERVATIONAL EVIDENCE FROM SDSS FOR A MERGER ORIGIN OF THE MILKY WAY'S THICK DISK

2010 ◽  
Vol 725 (2) ◽  
pp. L186-L190 ◽  
Author(s):  
Marion Dierickx ◽  
Rainer Klement ◽  
Hans-Walter Rix ◽  
Chao Liu
Keyword(s):  
Observational Evidence ◽  
Thick Disk

scholarly journals Disc growth and quenching

2019 ◽  
Vol 491 (1) ◽  
pp. L51-L55 ◽  
Author(s):  
Ying-jie Peng ◽  
Alvio Renzini
Keyword(s):  
Angular Momentum ◽  
Star Formation ◽  
Atomic Hydrogen ◽  
Observational Studies ◽  
Radial Flow ◽  
Observational Evidence ◽  
Molecular Gas ◽  
Scaling Relation ◽  
Star Forming ◽  
Large Factor

ABSTRACT Based on well-established scaling relation for star-forming galaxies as a function of redshift, we argue that the implied growth by a large factor of their angular momentum requires that the angular momentum of the inflowing gas fuelling star formation and disc growth must also secularly increase. We then propose that star formation in discs can cease (quench) once the accreted material (mainly atomic hydrogen) comes in with excessive angular momentum for sustaining an adequate radial flow of cold, molecular gas. Existing observational evidence supporting this scenario is mentioned, together with some future observational studies that may validate (or invalidate) it.

Peculiarity Parameters

1976 ◽  
Vol 32 ◽  
pp. 233-254
Author(s):  
H. M. Maitzen
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Theoretical Work ◽  
Observational Evidence ◽  
Rotator Model ◽  
Peculiar Behaviour ◽  
Field Spectrum ◽  
Oblique Rotator ◽  
Ap Stars ◽  
The Way

Ap stars are peculiar in many aspects. During this century astronomers have been trying to collect data about these and have found a confusing variety of peculiar behaviour even from star to star that Struve stated in 1942 that at least we know that these phenomena are not supernatural. A real push to start deeper theoretical work on Ap stars was given by an additional observational evidence, namely the discovery of magnetic fields on these stars by Babcock (1947). This originated the concept that magnetic fields are the cause for spectroscopic and photometric peculiarities. Great leaps for the astronomical mankind were the Oblique Rotator model by Stibbs (1950) and Deutsch (1954), which by the way provided mathematical tools for the later handling pulsar geometries, anti the discovery of phase coincidence of the extrema of magnetic field, spectrum and photometric variations (e.g. Jarzebowski, 1960).

The effect of aerosols on fog lifetime: observational evidence and model simulations

2020 ◽  
Author(s):  
Shuqi Yan ◽  
Bin Zhu ◽  
Tong Zhu ◽  
Chune Shi ◽  
Duanyang Liu ◽  
...  
Keyword(s):  
Observational Evidence ◽  
Model Simulations

Central kiloparsec of NGC 1326 observed with SINFONI

2020 ◽  
Vol 638 ◽  
pp. A53
Author(s):  
Nastaran Fazeli ◽  
Gerold Busch ◽  
Andreas Eckart ◽  
Françoise Combes ◽  
Persis Misquitta ◽  
...  
Keyword(s):  
Black Hole ◽  
Galaxy Evolution ◽  
Near Infrared ◽  
Velocity Fields ◽  
Molecular Gas ◽  
Nearby Galaxy ◽  
Stellar Content ◽  
Stellar Rotation ◽  
Supermassive Black Hole ◽  
Integral Field Spectrograph

Gas inflow processes in the vicinity of galactic nuclei play a crucial role in galaxy evolution and supermassive black hole growth. Exploring the central kiloparsec of galaxies is essential to shed more light on this subject. We present near-infrared H- and K-band results of the nuclear region of the nearby galaxy NGC 1326, observed with the integral-field spectrograph SINFONI mounted on the Very Large Telescope. The field of view covers 9″ × 9″ (650 × 650 pc2). Our work is concentrated on excitation conditions, morphology, and stellar content. The nucleus of NGC 1326 was classified as a LINER, however in our data we observed an absence of ionised gas emission in the central r ∼ 3″. We studied the morphology by analysing the distribution of ionised and molecular gas, and thereby detected an elliptically shaped, circum-nuclear star-forming ring at a mean radius of 300 pc. We estimate the starburst regions in the ring to be young with dominating ages of < 10 Myr. The molecular gas distribution also reveals an elongated east to west central structure about 3″ in radius, where gas is excited by slow or mild shock mechanisms. We calculate the ionised gas mass of 8 × 105 M⊙ completely concentrated in the nuclear ring and the warm molecular gas mass of 187 M⊙, from which half is concentrated in the ring and the other half in the elongated central structure. The stellar velocity fields show pure rotation in the plane of the galaxy. The gas velocity fields show similar rotation in the ring, but in the central elongated H2 structure they show much higher amplitudes and indications of further deviation from the stellar rotation in the central 1″ aperture. We suggest that the central 6″ elongated H2 structure might be a fast-rotating central disc. The CO(3–2) emission observations with the Atacama Large Millimeter/submillimeter Array reveal a central 1″ torus. In the central 1″ of the H2 velocity field and residual maps, we find indications for a further decoupled structure closer to a nuclear disc, which could be identified with the torus surrounding the supermassive black hole.

On the connection between the thick disk and the galactic bar

2014 ◽  
Vol 67-68 ◽  
pp. 405-405
Author(s):  
A. Spagna ◽  
A. Curir ◽  
R. Drimmel ◽  
M.G. Lattanzi ◽  
P. Re Fiorentin ◽  
...  
Keyword(s):  
Thick Disk
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