scholarly journals Optical supernova remnants in nearby galaxies and their influence on star formation rates derived from Hα emission

2014 ◽  
Vol 446 (1) ◽  
pp. 943-958 ◽  
Author(s):  
M. M. Vučetić ◽  
B. Arbutina ◽  
D. Urošević
Keyword(s):  
Star Formation ◽  
Supernova Remnants ◽  
Hα Emission ◽  
Nearby Galaxies

scholarly journals Probing the Baryon Cycle of Galaxies with SPICA Mid- and Far-Infrared Observations

2018 ◽  
Vol 35 ◽  
Author(s):  
F. F. S. van der Tak ◽  
S. C. Madden ◽  
P. Roelfsema ◽  
L. Armus ◽  
M. Baes ◽  
...  
Keyword(s):  
Fine Structure ◽  
Star Formation ◽  
Supernova Remnants ◽  
Interstellar Dust ◽  
Far Infrared ◽  
Turbulent Energy ◽  
Star Forming ◽  
Infrared Telescope ◽  
Nearby Galaxies ◽  
Fine Structure Lines

AbstractThe SPICA mid- and far-infrared telescope will address fundamental issues in our understanding of star formation and ISM physics in galaxies. A particular hallmark of SPICA is the outstanding sensitivity enabled by the cold telescope, optimised detectors, and wide instantaneous bandwidth throughout the mid- and far-infrared. The spectroscopic, imaging, and polarimetric observations that SPICA will be able to collect will help in clarifying the complex physical mechanisms which underlie the baryon cycle of galaxies. In particular, (i) the access to a large suite of atomic and ionic fine-structure lines for large samples of galaxies will shed light on the origin of the observed spread in star-formation rates within and between galaxies, (ii) observations of HD rotational lines (out to ~10 Mpc) and fine structure lines such as [C ii] 158 μm (out to ~100 Mpc) will clarify the main reservoirs of interstellar matter in galaxies, including phases where CO does not emit, (iii) far-infrared spectroscopy of dust and ice features will address uncertainties in the mass and composition of dust in galaxies, and the contributions of supernovae to the interstellar dust budget will be quantified by photometry and monitoring of supernova remnants in nearby galaxies, (iv) observations of far-infrared cooling lines such as [O i] 63 μm from star-forming molecular clouds in our Galaxy will evaluate the importance of shocks to dissipate turbulent energy. The paper concludes with requirements for the telescope and instruments, and recommendations for the observing strategy.

scholarly journals Detection and measurement of expanding ionized shells around young star clusters

2015 ◽  
Vol 11 (S315) ◽  
Author(s):  
John Beckman ◽  
Artemi Camps Fariña ◽  
Javier Zaragoza Cardiel ◽  
Joan Font
Keyword(s):  
Supernova Remnants ◽  
Spatial Scales ◽  
Young Star ◽  
Data Cube ◽  
Physical Parameters ◽  
Integral Field Spectroscopy ◽  
Hα Emission ◽  
Nearby Galaxies ◽  
Expanding Shells ◽  
Young Star Clusters

AbstractWe present a new method (BUBBLY) for detecting expanding components of ionized gas using integral field spectroscopy, showing its capabilities not only in detecting but also in obtaining the key physical parameters of the expanding shells: their expansion velocities and masses. The main advantages are that the detection is performed automatically via software and that we can derive most parameters of the shells, so it is suitable for detailed studies of feedback in nearby galaxies. The software can easily be configured to run on any data cube mapping an emission line over a spatial field. We also present results obtained by running BUBBLY on observations of Hα emission with the Fabry-Perot spectrograph GHαFaS: two sets of spectacular results at widely different spatial scales: the Antennae galaxies show multiple giant bubbles of size ~300pc around the brightest clusters, while inside a region in M33 we find three nested supernova remnants, with which we can study the feedback on the molecular gas surrounding the cluster.

scholarly journals Gas, Dust and Star Formation in Nearby Galaxies as Seen with the JCMT

2012 ◽  
Vol 8 (S292) ◽  
pp. 299-302
Author(s):  
José Ramón Sánchez-Gallego
Keyword(s):  
Star Formation ◽  
Radio Continuum ◽  
Ancillary Data ◽  
Group Interactions ◽  
Groups Of Galaxies ◽  
Star Forming ◽  
James Clerk Maxwell ◽  
Hα Emission ◽  
Low Metallicity ◽  
Nearby Galaxies

AbstractWe combine 12CO J = 3 − 2 for 155 nearby galaxies, obtained as part of the James Clerk Maxwell Telescope (JCMT) Nearby Galaxies Legacy Survey (NGLS), with star formation rates derived from Hα luminosities to probe the relation between warm, dense gas and star formation. These data are compared with ancillary data from the literature, including infrared (IR) and 1.4 GHz radio continuum luminosities and Hi masses. We find a good correlation between CO J = 3 − 2 luminosities and Hα-derived star formation rates (SFRs), which is in agreement with previous studies. Several groups of galaxies show a peculiar behaviour in the SFR(Hα) − LCOJ = 3 − 2 plot, which disappears when using IR data. We analyse these regions and propose several hypotheses to explain this behaviour, including group interactions and very recent (≲20 Myr) bursts of star formation only traced by Hα emission. While atomic hydrogen is hardly related with SFR, molecular and total gas (Hi + H2) show similar correlations with Hα luminosities. No correlation is found between CO J = 3−2 luminosity and metallicity, although galaxies with low metallicity are more likely to not be detected. We discuss that CO J = 3 − 2 does not seem to be a significantly better tracer of the star-forming gas, but its independence from metallicity may be used to constrain the conversion factor between CO and H2.

scholarly journals Global Evolutionary Effects in the Magellanic Clouds

1984 ◽  
Vol 108 ◽  
pp. 67-78
Author(s):  
James Lequeux
Keyword(s):  
Star Formation ◽  
Supernova Remnants ◽  
Average Rate ◽  
Age Distribution ◽  
Mass Function ◽  
Initial Mass Function ◽  
History Of ◽  
Hα Emission ◽  
Present Rate ◽  
Formation Number

Following Larson and Tinsley the integrated colours of the MCs from the UV to the red can be used to obtain the ratio of the present rate of star formation to the total amount of stars formed. Other tracers of recent star formation (number of bright stars, of supernova remnants, Hα emission, etc…) will be used to determine the present rate of star formation and to obtain some information on the initial mass function. The recent (t < a few 107 years) history of star formation in the MCs will then be discussed. Finally, it is found that the ratio present rate/total amount of stars ever formed is of the order of 0.1 Gyr−1 for both Clouds, implying a rather uniform average rate of star formation if the Cloud ages are the order of 1010 years. The results will be confronted with the metallicity-age relation and the age distribution of stars and clusters.

Recovering the star formation history of galaxies through spectral fitting: Current challenges

2019 ◽  
Vol 15 (S359) ◽  
pp. 386-390
Author(s):  
Lucimara P. Martins
Keyword(s):  
Star Formation ◽  
Mass Function ◽  
Initial Mass Function ◽  
Star Formation History ◽  
Stellar Spectra ◽  
Spectral Fitting ◽  
Formation History ◽  
History Of ◽  
Nearby Galaxies ◽  
Extract Information

AbstractWith the exception of some nearby galaxies, we cannot resolve stars individually. To recover the galaxies star formation history (SFH), the challenge is to extract information from their integrated spectrum. A widely used tool is the full spectral fitting technique. This consists of combining simple stellar populations (SSPs) of different ages and metallicities to match the integrated spectrum. This technique works well for optical spectra, for metallicities near solar and chemical histories not much different from our Galaxy. For everything else there is room for improvement. With telescopes being able to explore further and further away, and beyond the optical, the improvement of this type of tool is crucial. SSPs use as ingredients isochrones, an initial mass function, and a library of stellar spectra. My focus are the stellar libraries, key ingredient for SSPs. Here I talk about the latest developments of stellar libraries, how they influence the SSPs and how to improve them.

VLA-ANGST: Star Formation History and ISM Feedback in Nearby Galaxies

2008 ◽  
pp. 321-322
Author(s):  
Jurgen Ott ◽  
Evan Skillman ◽  
Julianne Dalcanton ◽  
Fabian Walter ◽  
Andrew West ◽  
...  
Keyword(s):  
Star Formation ◽  
Star Formation History ◽  
Formation History ◽  
Nearby Galaxies

scholarly journals SKA studies of nearby galaxies: star-formation, accretion processes and molecular gas across all environments

2015 ◽  
Author(s):  
Rob J. Beswick ◽  
Elias Brinks ◽  
Miguel Perez-Torres ◽  
Anita Richards ◽  
Susanne Aalto ◽  
...  
Keyword(s):  
Star Formation ◽  
Molecular Gas ◽  
Nearby Galaxies

scholarly journals The Galactic Center compared with nuclei of nearby galaxies

2016 ◽  
Vol 11 (S322) ◽  
pp. 245-252 ◽  
Author(s):  
Francoise Combes
Keyword(s):  
Star Formation ◽  
Galactic Center ◽  
Galactic Nuclei ◽  
Molecular Outflows ◽  
Star Formation Activity ◽  
Nearby Galaxies

AbstractUnderstanding our Galactic Center is easier with insights from nearby galactic nuclei. Both the star formation activity in nuclear gas disks, driven by bars and nuclear bars, and the fueling of low-luminosity AGN, followed by feedback of jets, driving molecular outflows, were certainly present in our Galactic Center, which appears now quenched. Comparisons and diagnostics are reviewed, in particular of m = 2 and m = 1 modes, lopsidedness, different disk orientations, and fossil evidences of activity and feedback.

scholarly journals MAGMO: polarimetry of 1720-MHz OH masers towards southern star-forming regions

2020 ◽  
Vol 493 (1) ◽  
pp. 199-233 ◽  
Author(s):  
C S Ogbodo ◽  
J A Green ◽  
J R Dawson ◽  
S L Breen ◽  
S A Mao ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Star Formation ◽  
Ground State ◽  
Supernova Remnants ◽  
Galactic Centre ◽  
Galactic Magnetic Field ◽  
Field Orientation ◽  
Star Forming ◽  
Star Forming Regions ◽  
Methanol Masers

ABSTRACT From targeted observations of ground-state hydroxyl (OH) masers towards 702 Methanol Multibeam survey 6.7-GHz methanol masers, in the Galactic longitude range from 186° through the Galactic Centre to 20°, made as part of the ‘MAGMO’ (Mapping the Galactic Magnetic field through OH masers) project, we present the physical and polarization properties of the 1720-MHz OH maser transition, including the identification of Zeeman pairs. We present 10 new and 23 previously catalogued 1720-MHz OH maser sources detected towards star-forming regions (SFRs). In addition, we also detected 16 1720-MHz OH masers associated with supernova remnants and two sites of diffuse OH emission. Towards the 33 star formation masers, we identify 44 Zeeman pairs, implying magnetic field strengths ranging from −11.4 to +13.2 mG, and a median magnetic field strength of |BLOS| ∼ 6 mG. With limited statistics, we present the in situ magnetic field orientation of the masers and the Galactic magnetic field distribution revealed by the 1720-MHz transition. We also examine the association statistics of 1720-MHz OH SFR masers with other ground-state OH masers, excited-state OH masers, class I and class II methanol masers, and water masers, and compare maser positions with mid-infrared images of the parent SFRs. Of the 33 1720-MHz star formation masers, 10 are offset from their central exciting sources, and appear to be associated with outflow activity.

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