scholarly journals Les galaxies de type précoce

Galaxies ◽  
2021 ◽  
pp. 115-159
Author(s):  
Eric EMSELLEM
Keyword(s):  

Les galaxies de type précoce ou ETG pour Early-Type Galaxies regroupent les galaxies elliptiques (E) et lenticulaires (S0). Elles représentent 33 % de la lumière émise par les différentes galaxies mais environ 50 % de la masse d’étoiles. Elles sont composées en général de vieilles étoiles, d’âge 8 milliards d’années ou plus, qui possèdent très peu de rotation. Leur équilibre gravitationnel est dû en grande partie à une dispersion anisotrope de vitesses. Elles ne contiennent que très peu de gaz, et les plus massives se sont formées par la fusion de plusieurs galaxies spirales. Cette étude montre comment la proportion entre disque et sphéroïde varie le long d’une séquence, en fonction du degré de rotation, de l’âge, de la métallicité, de la masse et de la concentration.

1966 ◽  
Vol 24 ◽  
pp. 77-90 ◽  
Author(s):  
D. Chalonge

Several years ago a three-parameter system of stellar classification has been proposed (1, 2), for the early-type stars (O-G): it was an improvement on the two-parameter system described by Barbier and Chalonge (3).


2019 ◽  
Author(s):  
Alice Lelliott ◽  
Supriyo Basu ◽  
Rachel Besser
Keyword(s):  

Diabetes ◽  
2019 ◽  
Vol 68 (Supplement 1) ◽  
pp. 1561-P
Author(s):  
SUZANNE CRAFT ◽  
AMY CLAXTON ◽  
MARK TRIPPUTI ◽  
SHARON EDELSTEIN ◽  
SILVA A. ARSLANIAN ◽  
...  

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 1834-P
Author(s):  
SVIATLANA V. ZHYZHNEUSKAYA ◽  
AHMAD AL-MRABEH ◽  
CARL PETERS ◽  
ALISON C. BARNES ◽  
KIEREN G. HOLLINGSWORTH ◽  
...  

Diabetes ◽  
1984 ◽  
Vol 33 (6) ◽  
pp. 516-521 ◽  
Author(s):  
O. P. Ganda ◽  
S. Srikanta ◽  
S. J. Brink ◽  
M. A. Morris ◽  
R. E. Gleason ◽  
...  

1999 ◽  
Vol 518 (2) ◽  
pp. 890-900 ◽  
Author(s):  
Jessica M. Chapman ◽  
Claus Leitherer ◽  
Barbel Koribalski ◽  
Roderick Bouter ◽  
Michelle Storey

1999 ◽  
Vol 514 (2) ◽  
pp. 844-855 ◽  
Author(s):  
A. Finoguenov ◽  
C. Jones ◽  
W. Forman ◽  
L. David

1980 ◽  
Vol 4 (1) ◽  
pp. 95-97 ◽  
Author(s):  
J. B. Whiteoak ◽  
F. F. Gardner

As part of a general investigation of interstellar clouds associated with southern HII regions we have begun a high-resolution study of the sodium D-line absorption in the directions of early-type stars that are likely to be associated with or located behind the clouds.


2020 ◽  
Vol 15 (S359) ◽  
pp. 454-456
Author(s):  
T. V. Ricci ◽  
J. E. Steiner ◽  
R. B. Menezes

AbstractIn this work, we present preliminary results regarding the nuclear emission lines of a statistically complete sample of 56 early-type galaxies that are part of the Deep Integral Field Spectroscopy View of Nuclei of Galaxies (DIVING3D) Project. All early type galaxies (ETGs) were observed with the Gemini Multi-Object Spectrograph Integral Field Unit (GMOS-IFU) installed on the Gemini South Telescope. We detected emission lines in 93% of the sample, mostly low-ionization nuclear emission-line region galaxies (LINERs). We did not find Transition Objects nor H II regions in the sample. Type 1 objects are seen in ∼23% of the galaxies.


1998 ◽  
Vol 11 (1) ◽  
pp. 566-566
Author(s):  
C. Jaschek ◽  
A.E. Gómez

We have analysed the standards of the MK system in the B0-F5 spectral region with the help of Hipparcos parallaxes, using only stars for which the error on the absolute magnitude is ≤ 0.3 mag. The sample stars (about one hundred) were scrutinized for companions and for interstellar extinction. We find that the main sequence is a wide band and that, although in general giants and dwarfs have different absolute magnitudes, the separation between luminosity class V and III is not clear. We conclude that there is no strict relation between luminosity class and absolute magnitude. The relation is only a statistical one and has a large intrinsic dispersion. We have analysed similarly the system of standards defined by Garrison and Gray (1994) separating low and high rotational velocity standards. We find similar effects as in the original MK system.


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