The integrated spectra of nearby galaxies - General properties and emission-line spectra

1992 ◽  
Vol 388 ◽  
pp. 310 ◽  
Author(s):  
Robert C., Jr. Kennicutt
Keyword(s):  
Emission Line ◽  
General Properties ◽  
Nearby Galaxies ◽  
Galaxies General

scholarly journals Upper limits on the mass of supermassive black holes from STIS archival data

2007 ◽  
Vol 3 (S245) ◽  
pp. 233-234
Author(s):  
A. Beifiori ◽  
E. M. Corsini ◽  
E. Dalla Bontà ◽  
A. Pizzella ◽  
L. Coccato ◽  
...  
Keyword(s):  
Black Holes ◽  
Emission Line ◽  
Supermassive Black Holes ◽  
Archival Data ◽  
Early Type ◽  
Preliminary Results ◽  
Upper Limits ◽  
Nearby Galaxies ◽  
Line Widths

AbstractThe growth of supermassive black holes (SMBHs) appears to be closely linked with the formation of spheroids. There is a pressing need to acquire better statistics on SMBH masses, since the existing samples are preferentially weighted toward early-type galaxies with very massive SMBHs. With this motivation we started a project aimed at measuring upper limits on the mass of the SMBHs that can be present in the center of all the nearby galaxies (D < 100 Mpc) for which STIS/G750M spectra are available in the HST archive. These upper limits will be derived by modeling the central emission-line widths ([N II] λλ6548, 6583, Hα and [S II] λλ6716, 6731) observed over an aperture of ~01 (R < 50 pc). Here we present our preliminary results for a subsample of 76 bulges.

scholarly journals The dark matter interpretation of the 3.5-keV line is inconsistent with blank-sky observations

Science ◽  
2020 ◽  
Vol 367 (6485) ◽  
pp. 1465-1467 ◽  
Author(s):  
Christopher Dessert ◽  
Nicholas L. Rodd ◽  
Benjamin R. Safdi
Keyword(s):  
Dark Matter ◽  
Emission Line ◽  
Decay Rate ◽  
Milky Way ◽  
Line Emission ◽  
Mass Range ◽  
Sterile Neutrinos ◽  
X Ray ◽  
Upper Limit ◽  
Nearby Galaxies

Observations of nearby galaxies and galaxy clusters have reported an unexpected x-ray emission line around 3.5 kilo–electron volts (keV). Proposals to explain this line include decaying dark matter—in particular, that the decay of sterile neutrinos with a mass around 7 keV could match the available data. If this interpretation is correct, the 3.5-keV line should also be emitted by dark matter in the halo of the Milky Way. We used more than 30 megaseconds of XMM-Newton (X-ray Multi-Mirror Mission) blank-sky observations to test this hypothesis, finding no evidence of the 3.5-keV line emission from the Milky Way halo. We set an upper limit on the decay rate of dark matter in this mass range, which is inconsistent with the possibility that the 3.5-keV line originates from dark matter decay.

scholarly journals The UM/CTIO Magellanic Cloud Emission-line Survey

1999 ◽  
Vol 190 ◽  
pp. 28-31 ◽  
Author(s):  
R. Chris Smith ◽  
Keyword(s):  
Interstellar Medium ◽  
Emission Line ◽  
Supernova Remnants ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
H Ii Regions ◽  
Deep Imaging ◽  
Small Scales ◽  
Nearby Galaxies ◽  
Line Survey

The Magellanic Clouds are unique in providing sites to study the interstellar medium (ISM) and its components at all scales. To promote the pursuit of such studies, we have begun the Magellanic Cloud Emission-line Survey (MCELS), a deep imaging survey of both of these nearby galaxies in the emission of Hα, [S II], and [O III]. The emission-line images will be used in detailed optical and multiwavelength studies of H II regions, supernova remnants, planetary nebulae, superbubbles, and supergiant shells. Together with parallel surveys at other wavelengths, this survey will provide the foundation upon which to build a deeper understanding of the ISM in the Clouds and other galaxies, from small scales (~1 pc) all the way up to global scales. We present a sample of recent and current work using the MCELS dataset.

scholarly journals Dust emission in star-forming dwarf galaxies: General properties and the nature of the submm excess

2014 ◽  
Vol 570 ◽  
pp. A97 ◽  
Author(s):  
Y. I. Izotov ◽  
N. G. Guseva ◽  
K. J. Fricke ◽  
E. Krügel ◽  
C. Henkel
Keyword(s):  
Dwarf Galaxies ◽  
Dust Emission ◽  
Star Forming ◽  
General Properties ◽  
Galaxies General

scholarly journals Deep spectroscopy of the dwarf spheroidal NGC 185

2011 ◽  
Vol 7 (S283) ◽  
pp. 370-371
Author(s):  
Denise R. Gonçalves ◽  
Laura Magrini ◽  
Lucimara P. Martins ◽  
Ana M. Teodorescu ◽  
Cintia Quireza ◽  
...  
Keyword(s):  
Emission Line ◽  
Chemical Evolution ◽  
Dwarf Galaxies ◽  
Seyfert Galaxy ◽  
Ionization Mechanisms ◽  
The Galaxy ◽  
Nearby Galaxies ◽  
Formation And Evolution ◽  
Nuclear Regions ◽  
Galaxy Population

AbstractDwarf galaxies are crucial to understand the formation and evolution of galaxies, since they constitute the most abundant galaxy population. Abundance ratios and their variations due to star formation and inflow/outflow of gas are key constraints to chemical evolution models. The determination of these abundances in the dwarf galaxies of the Local Universe is thus of extreme importance. NGC 185 is one of the four brightest dwarf companions of M31, but unlike the other three it has an important content of gas and dust. Interestingly enough, in an optical survey of bright nearby galaxies NGC 185 was classified as a Seyfert galaxy based on its integrated emission-line ratios in the nuclear regions. However, although its emission lines formally place it in the category of Seyfert it is probable that this galaxy does not contain a genuine active nucleus. In this contribution, we resume, firstly, our results of an empirical study of the galaxy, on which we characterise its emission-line population and obtain planetary nebulae abundance ratios (Gonçalves et al. 2012). And, secondly, we discuss our attempt to identify the possible ionization mechanisms for NGC 185 enlighting the controversial classification of this galaxy dwarf spheroidal (dSph) as well as Seyfert, via stellar population synthesis and chemical evolution modelling (Martins et al. 2011).

scholarly journals Nuclear Activity in the Hickson Compact Groups of Galaxies

1999 ◽  
Vol 186 ◽  
pp. 418-418
Author(s):  
M. Shimada ◽  
S. Nishiura ◽  
Y. Ohyama ◽  
T. Murayama ◽  
Y. Taniguchi
Keyword(s):  
Emission Line ◽  
The Other ◽  
Compact Groups ◽  
Early Type ◽  
Late Type ◽  
No Emission ◽  
Nuclear Activity ◽  
Groups Of Galaxies ◽  
Nearby Galaxies ◽  
Hickson Compact Groups

In order to study environmental effects on the nuclear activity in galaxies, we have been conducting a spectroscopic study of Hickson Compact Groups of galaxies (HCGs, Hickson 1982) which are the densest agglomeration of galaxies. We obtained nuclear spectra of 62 galaxies in 29 HCGs in the spectral range 6200–7000Å with the 188cm telescope at Okayama Astrophysical Observatory. These spectra were classified into the three types by using the emission line ratio [NII]λ6583/Hα; (1) AGN: [NII]λ6583/Hα >0.6, (2) HII nuclei: [NII]λ6583/Hα <0.6, and (3) Absorption: no emission line. We compared the nuclear activity of galaxies in HCGs with that of nearby galaxies (Ho 1996; Ho, Filippenko & Sargent 1997) which provides a representative sample of field galaxies. In early-type spirals (Sa-Sbc), the fraction of HII nuclei in HCGs is smaller than that in the field galaxies, while the fraction of absorption in HCGs is larger than that in field galaxies. On the other hand, in early-type galaxies (E-S0a) and late-type spirals (Sc-P), we found little difference in the nuclear activity between HCGs and field galaxies.

scholarly journals The Galactic center: not an active galactic nucleus

2013 ◽  
Vol 9 (S303) ◽  
pp. 54-58
Author(s):  
Deokkeun An ◽  
Solange V. Ramírez ◽  
Kris Sellgren
Keyword(s):  
Interstellar Medium ◽  
Emission Line ◽  
Active Galactic Nuclei ◽  
Active Galactic Nucleus ◽  
Galactic Center ◽  
Galactic Nuclei ◽  
Extensive Area ◽  
Star Forming ◽  
Nearby Galaxies

AbstractWe present 10 μm – 35μm Spitzer spectra of the interstellar medium in the central molecular zone (CMZ), the central 210 pc × 60 pc of the Galactic center (GC). We present maps of the CMZ in ionic and H2 emission, covering a more extensive area than earlier spectroscopic surveys in this region. We compare diagnostic line ratios measured in the Spitzer Infrared Nearby Galaxies Survey to our data. Previous work shows that forbidden line ratios can distinguish star-forming galaxies from low-ionization nuclear emission-line regions (LINERs) and active galactic nuclei (AGNs). Our GC line ratios agree with star-forming galaxies and not with LINERs or AGNs.

scholarly journals Starburst radio galaxies: general properties, evolutionary histories and triggering

2011 ◽  
pp. no-no ◽  
Author(s):  
C. Tadhunter ◽  
J. Holt ◽  
R. González Delgado ◽  
J. Rodríguez Zaurín ◽  
M. Villar-Martín ◽  
...  
Keyword(s):  
Radio Galaxies ◽  
General Properties ◽  
Galaxies General

scholarly journals Local analogs of high-redshift galaxies: Interstellar medium conditions

2016 ◽  
Vol 11 (S321) ◽  
pp. 333-335
Author(s):  
Fuyan Bian ◽  
Lisa J. Kewley ◽  
Michael A. Dopita ◽  
Stephanie Juneau
Keyword(s):  
Interstellar Medium ◽  
Emission Line ◽  
Surface Density ◽  
High Redshift ◽  
Electron Densities ◽  
High Redshift Galaxies ◽  
Diagnostic Diagram ◽  
Nearby Galaxies ◽  
The Difference ◽  
Redshift Galaxies

AbstractLocal analog galaxies play an important role in understanding the properties of high-redshift galaxies. We present a method to select a type of local analog that closely resembles the ionized interstellar medium conditions in high-redshift galaxies. These galaxies are selected based on their locations in the [O III]/Hβ versus [N II]/Hα nebular emission-line diagnostic diagram. The ionization parameters and electron densities in these analogs are comparable to those in z ≃ 2 − 3 galaxies, but higher than those in normal SDSS galaxies by ≃ 0.6 dex and ≃ 0.9 dex, respectively. We find that the high sSFR and SFR surface density can enhance the electron densities and the ionization parameters, but still cannot fully explain the difference in ISM condition between nearby galaxies and the local analogs/high-redshift galaxies.

Extended optical line emission associated with radio galaxies

1986 ◽  
Vol 64 (4) ◽  
pp. 392-397 ◽  
Author(s):  
Wil van Breugel
Keyword(s):  
Emission Line ◽  
Ambient Medium ◽  
Line Emission ◽  
Optical Emission ◽  
Radio Galaxies ◽  
General Properties ◽  
Extragalactic Jets ◽  
Optical Line

Observations of radio galaxies that have extended optical emission-line regions provide a new way of studying the interaction of extragalactic jets with their ambient medium. Their general properties are briefly reviewed and are illustrated using recent results on 4C 29.30 and Minkowski's Object.

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