scholarly journals The Nature of High HI Mass-to-Light Ratio Galaxies

2004 ◽  
Vol 217 ◽  
pp. 48-49
Author(s):  
Bradley E. Warren ◽  
Helmut Jerjen ◽  
Bärbel S. Koribalski
Keyword(s):  
Dwarf Galaxies ◽  
Bright Galaxy ◽  
Preliminary Results ◽  
Multi Wavelength

We present here preliminary results of our multi-wavelength investigation into high HI mass-to-light ratio dwarf galaxies identified in the HIPASS Bright Galaxy Catalog.

scholarly journals HI Rotation of Dwarf Galaxies with Unusually High HI Mass-to-Light Ratios

2004 ◽  
Vol 220 ◽  
pp. 369-370
Author(s):  
Bradley E. Warren ◽  
Helmut Jerjen ◽  
Bärbel S. Koribalski
Keyword(s):  
Dwarf Galaxies ◽  
Bright Galaxy ◽  
Preliminary Results ◽  
Multi Wavelength

We present here preliminary results of a multi-wavelength investigation into high HI mass-to-light ratio dwarf galaxies identified in the HIPASS Bright Galaxy Catalog. Here we focus on the rotational properties of some of the galaxies.

scholarly journals Dwarf Galaxies in Nearby Groups

1999 ◽  
Vol 171 ◽  
pp. 154-156
Author(s):  
T. Bremnes ◽  
B. Binggeli ◽  
P. Prugniel
Keyword(s):  
Surface Brightness ◽  
Dwarf Galaxies ◽  
Photometric Data ◽  
Preliminary Results ◽  
Central Surface ◽  
Total Magnitude ◽  
Evolutionary Connection

AbstractWe present preliminary results from two observing campaigns where global photometric data for most dwarf galaxies in the M81 and M101 groups as well as some field dwarfs were obtained. The galaxies in the denser M81 group are more often of dwarf elliptical type and are redder and fainter than those of the M101 group and surrounding field, which are mostly of the dwarf irregular types. But both types follow the same total magnitude - central surface brightness relation, so there might be an evolutionary connection between the two classes.

The outbursts of comet 29P/SW-1 and C/2020 R4 (ATLAS)

2021 ◽  
Author(s):  
Zhong-Yi Lin ◽  
Michael S. P. Kelly ◽  
Huen-Wing Ip
Keyword(s):  
Gas Production ◽  
Active Period ◽  
Production Rates ◽  
Preliminary Results ◽  
Long Period ◽  
Level Of Activity ◽  
Multi Wavelength ◽  
Dust Coma ◽  
Period Comet

<p>We present an analysis of the dynamic dust coma of Centaur 29P/Schewassmann-Wachmann 1 and long-period comet C/2020 R4 (Atlas). Comet P/SW1 has exhibited a considerable level of activity (so-called outbursts) since its discovery in 1925. In 2011, we found the morphology of comet P/SW 1 showed dust features in the form of jets, spirals and shells. This year, we have obtained multi-wavelength observations of 29P/SW 1's dust coma at Lulin observatory and we will present preliminary results including the morphological analysis and the colour (B-V, V-R, and R-I) investigation of the dust coma when comet is at quiet and active period.</p> <p>At least three outbursts found within two weeks from comet Atlas is unusual for long-period comet. However, we didn’t find any new jet features and fragments from the morphology of comet Atlas. Except for the color investigation during the outburst, we will also give the dust/gas production rates in the comparison between pre- and post-outbursts.</p>

Chemical composition of globular clusters in dwarf galaxies

2019 ◽  
Vol 14 (S351) ◽  
pp. 317-320
Author(s):  
Søren S. Larsen
Keyword(s):  
Chemical Composition ◽  
Globular Clusters ◽  
Milky Way ◽  
Local Group ◽  
Dwarf Galaxies ◽  
Chemical Abundances ◽  
Preliminary Results ◽  
Detailed Chemical

AbstractThis contribution gives an update on on-going efforts to characterise the detailed chemical abundances of Local Group globular clusters (GCs) from integrated-light spectroscopy. Observations of a sample of 20 GCs so far, located primarily within dwarf galaxies, show that at low metallicities the [α/Fe] ratios are generally indistinguishable from those in Milky Way GCs. However, the “knee” above which [α/Fe] decreases towards Solar-scaled values occurs at lower metallicities in the dwarfs, implying that GCs follow the same trends seen in field stars. Efforts are underway to establish NLTE corrections for integrated-light abundance measurements, and preliminary results for Mn are discussed.

scholarly journals A Multi-Wavelength Study of X-ray Selected AGN

1989 ◽  
Vol 134 ◽  
pp. 199-200
Author(s):  
R. J. V. Brissenden ◽  
I. R. Tuohy ◽  
G. V. Bicknell ◽  
R. A. Remillard ◽  
D. A. Schwartz
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
High Energy ◽  
Astronomy Observatory ◽  
X Ray ◽  
Preliminary Results ◽  
Multi Wavelength ◽  
Uv Excess ◽  
Modulation Collimator

A sample of Active Galactic Nuclei (AGN) have been discovered during a program to identify the optical counterparts of X-ray sources detected by the Modulation Collimator experiment of the High Energy Astronomy Observatory-1 (HEAO-1). UV-excess techniques were used to identify the X-ray sources (Remillard et al. 1986) and the details of the identifications are given elsewhere (Remillard et al. 1988, Brissenden et al. 1988). We report here the preliminary results of a multi-wavelength study of these new AGN.

scholarly journals Tidal dwarf galaxies as laboratories of star formation and cosmology

2006 ◽  
Vol 2 (S237) ◽  
pp. 323-330 ◽  
Author(s):  
Pierre-Alain Duc ◽  
Frédéric Bournaud ◽  
Médéric Boquien
Keyword(s):  
Dark Matter ◽  
Star Formation ◽  
Numerical Simulations ◽  
Dwarf Galaxies ◽  
Star Clusters ◽  
Dense Core ◽  
Multi Wavelength ◽  
Interacting Systems ◽  
Super Star Clusters ◽  
Tidal Tails

AbstractStar formation may take place in a variety of locations in interacting systems: in the dense core of mergers, in the shock regions at the interface of the colliding galaxies and even within the tidal debris expelled into the intergalactic medium. Along tidal tails, objects may be formed with masses ranging from those of super-star clusters to dwarf galaxies: the so-called Tidal Dwarf Galaxies (TDGs). Based on a set of multi-wavelength observations and extensive numerical simulations, we show how TDGs may simultaneously be used as laboratories to study the process of star-formation (SFE, IMF) in a specific environment and as probes of various cosmological properties, such as the distribution of dark matter and satellites around galaxies.

scholarly journals The frequency and properties of young tidal dwarf galaxies in nearby groups

2016 ◽  
Vol 11 (S321) ◽  
pp. 238-240
Author(s):  
K. Lee-Waddell ◽  
K. Spekkens ◽  
P. Chandra ◽  
N. Patra ◽  
J.-C. Cuillandre ◽  
...  
Keyword(s):  
Dwarf Galaxies ◽  
Dwarf Galaxy ◽  
Optical Photometry ◽  
Galaxy Groups ◽  
Multi Wavelength ◽  
Group Members ◽  
Low Mass ◽  
Mass Group ◽  
Galaxy Populations ◽  
Stellar Properties

AbstractWe present the results of a multi-wavelength investigation of the dwarf galaxy populations in three interacting galaxy groups: NGC 871/6/7, NGC 3166/9, NGC 4725/47. Using degree-scale Giant Metrewave Radio Telescope Hi mosaics and deep optical photometry from the Canada-France-Hawaii Telescope, we measured the Hi and stellar properties of the gas-rich low-mass group members to classify each one as a classical dwarf galaxy, a short-lived tidal knot or a tidal dwarf galaxy (TDG). Our observations detect several dwarf irregulars and various tidal knots. We identify four potentially long-lived tidal objects in the three groups, implying that TDGs are not readily produced. The tidal objects examined in this small survey also appear to have a wider variety of properties than TDGs formed in current simulations.

scholarly journals Orbits versus Star Formation Histories: A Progress Report

1999 ◽  
Vol 192 ◽  
pp. 447-450 ◽  
Author(s):  
Eva K. Grebel ◽  
Tsafrir Kolatt ◽  
Wolfgang Brandner
Keyword(s):  
Star Formation ◽  
Milky Way ◽  
Statistical Approach ◽  
Local Group ◽  
Dwarf Galaxies ◽  
Progress Report ◽  
Polar Plane ◽  
Preliminary Results ◽  
Star Formation Histories

Milky Way dwarf companions and satellites of distant spirals seem to show a preference for polar orbits. We suggest that five out of six M31 dwarf spheroidal companions as well as two dwarf irregulars may also be located near a polar plane.We briefly discuss preliminary results from a statistical approach to study correlations between star formation histories and orbits of Local Group dwarf galaxies, such as a possible correlation between star formation episodes and galaxy separations.

scholarly journals Multi-wavelength study of a new sample of blue compact dwarf galaxies

2002 ◽  
Vol 391 (2) ◽  
pp. 487-508 ◽  
Author(s):  
A. R. Petrosian ◽  
T. Movsessian ◽  
G. Comte ◽  
D. Kunth ◽  
S. Dodonov
Keyword(s):  
Dwarf Galaxies ◽  
Multi Wavelength
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