scholarly journals The ALPINE–ALMA [C ii] Survey: Size of Individual Star-forming Galaxies at z = 4–6 and Their Extended Halo Structure

2020 ◽  
Vol 900 (1) ◽  
pp. 1 ◽  
Author(s):  
Seiji Fujimoto ◽  
John D. Silverman ◽  
Matthieu Bethermin ◽  
Michele Ginolfi ◽  
Gareth C. Jones ◽  
...  
Keyword(s):  
Halo Structure ◽  
Star Forming ◽  
Individual Star

scholarly journals The star formation process in the Magellanic Clouds

2008 ◽  
Vol 4 (S256) ◽  
pp. 191-202
Author(s):  
J. M. Oliveira
Keyword(s):  
Star Formation ◽  
High Redshift ◽  
Critical Density ◽  
Mass Function ◽  
Magellanic Clouds ◽  
Initial Mass Function ◽  
Star Forming ◽  
Bridge Span ◽  
Individual Star ◽  
Low Metallicity

AbstractThe Magellanic Clouds offer unique opportunities to study star formation both on the global scales of an interacting system of gas-rich galaxies, as well as on the scales of individual star-forming clouds. The interstellar media of the Small and Large Magellanic Clouds and their connecting bridge, span a range in (low) metallicities and gas density. This allows us to study star formation near the critical density and gain an understanding of how tidal dwarfs might form; the low metallicity of the SMC in particular is typical of galaxies during the early phases of their assembly, and studies of star formation in the SMC provide a stepping stone to understand star formation at high redshift where these processes can not be directly observed. In this review, I introduce the different environments encountered in the Magellanic System and compare these with the Schmidt-Kennicutt law and the predicted efficiencies of various chemo-physical processes. I then concentrate on three aspects that are of particular importance: the chemistry of the embedded stages of star formation, the Initial Mass Function, and feedback effects from massive stars and its ability to trigger further star formation.

scholarly journals The MUSE Hubble Ultra Deep Field Survey

2017 ◽  
Vol 608 ◽  
pp. A8 ◽  
Author(s):  
Floriane Leclercq ◽  
Roland Bacon ◽  
Lutz Wisotzki ◽  
Peter Mitchell ◽  
Thibault Garel ◽  
...  
Keyword(s):  
High Redshift ◽  
Dark Matter Halo ◽  
Star Forming ◽  
Star Forming Regions ◽  
Size Evolution ◽  
Individual Star ◽  
Hubble Ultra Deep Field ◽  
Gas Accretion ◽  
Scale Length

We report the detection of extended Lyα haloes around 145 individual star-forming galaxies at redshifts 3 ≤ z ≤ 6 in the Hubble Ultra Deep Field observed with the Multi-Unit Spectroscopic Explorer (MUSE) at ESO-VLT. Our sample consists of continuum-faint (− 15 ≥ MUV ≥ −22) Lyα emitters (LAEs). Using a 2D, two-component (continuum-like and halo) decomposition of Lyα emission assuming circular exponential distributions, we measure scale lengths and luminosities of Lyα haloes. We find that 80% of our objects having reliable Lyα halo measurements show Lyα emission that is significantly more extended than the UV continuum detected by HST (by a factor ≈4 to >20). The median exponential scale length of the Lyα haloes in our sample is ≈4.5 kpc with a few haloes exceeding 10 kpc. By comparing the maximal detected extent of the Lyα emission with the predicted dark matter halo virial radii of simulated galaxies, we show that the detected Lyα emission of our selected sample of Lyα emitters probes a significant portion of the cold circum-galactic medium of these galaxies (>50% in average). This result therefore shows that there must be significant HI reservoirs in the circum-galactic medium and reinforces the idea that Lyα haloes are ubiquitous around high-redshift Lyα emitting galaxies. Our characterization of the Lyα haloes indicates that the majority of the Lyα flux comes from the halo (≈65%) and that their scale lengths seem to be linked to the UV properties of the galaxies (sizes and magnitudes). We do not observe a significant Lyα halo size evolution with redshift, although our sample for z> 5 is very small. We also explore the diversity of the Lyα line profiles in our sample and we find that the Lyα lines cover a large range of full width at half maximum (FWHM) from 118 to 512 km s-1. While the FWHM does not seem to be correlated to the Lyα scale length, most compact Lyα haloes and those that are not detected with high significance tend to have narrower Lyα profiles (<350 km s-1). Finally, we investigate the origin of the extended Lyα emission but we conclude that our data do not allow us to disentangle the possible processes, i.e. scattering from star-forming regions, fluorescence, cooling radiation from cold gas accretion, and emission from satellite galaxies.

scholarly journals Probing Individual Star Forming Regions Within Strongly Lensed Galaxies at z > 1

2014 ◽  
Vol 10 (S309) ◽  
pp. 251-254
Author(s):  
Matthew B. Bayliss ◽  
Jane R. Rigby ◽  
Keren Sharon ◽  
Michael D. Gladders ◽  
Eva Wuyts
Keyword(s):  
Star Formation ◽  
Gravitational Lensing ◽  
Velocity Structure ◽  
Spectroscopic Studies ◽  
Uv Spectra ◽  
Star Forming ◽  
Star Forming Regions ◽  
Wide Range ◽  
Individual Star ◽  
Multi Wavelength

AbstractStar formation occurs on physical scales corresponding to individual star forming regions, typically of order ∼100 parsecs in size, but current observational facilities cannot resolve these scales within field galaxies beyond the local universe. However, the magnification from strong gravitational lensing allows us to measure the properties of these discrete star forming regions within galaxies in the distant universe. New results from multi-wavelength spectroscopic studies of a sample of extremely bright, highly magnified lensed galaxies are revealing the complexity of star formation on sub-galaxy scales during the era of peak star formation in the universe. We find a wide range of properties in the rest-frame UV spectra of individual galaxies, as well as in spectra that originate from different star forming regions within the same galaxy. Large variations in the strengths and velocity structure of Lyman-alpha and strong P Cygni lines such as C IV, and MgII provide new insights into the astrophysical relationships between extremely massive stars, the elemental abundances and physical properties of the nebular gas those stars ionize, and the galactic-scale outflows they power.

scholarly journals The Spatially-Resolved Star Formation History of the M31 Disk from Resolved Stellar Populations

2014 ◽  
Vol 10 (S309) ◽  
pp. 57-60
Author(s):  
Alexia R. Lewis ◽  
Julianne J. Dalcanton ◽  
Andrew E. Dolphin ◽  
Daniel R. Weisz ◽  
Benjamin F. Williams ◽  
...  
Keyword(s):  
Star Formation ◽  
Stellar Populations ◽  
Star Formation History ◽  
Star Forming ◽  
Spatially Resolved ◽  
Star Forming Regions ◽  
Star Formation Activity ◽  
Individual Star ◽  
Star Formation Histories ◽  
Optical Color

AbstractThe Panchromatic Hubble Andromeda Treasury (PHAT) is an HST multi-cycle treasury program that has mapped the resolved stellar populations of ∼1/3 of the disk of M31 from the UV through the near-IR. This data provides color and luminosity information for more than 150 million stars. Using stellar evolution models, we model the optical color-magnitude diagram to derive spatially-resolved recent star formation histories (SFHs) over large areas of M31 with 100 pc resolution. These include individual star-forming regions as well as quiescent portions of the disk. With these gridded SFHs, we create movies of star formation activity to study the evolution of individual star-forming events across the disk. We analyze the structure of star formation and examine the relation between star formation and gas throughout the disk and particularly in the 10-kpc star-forming ring. We find that the ring has been continuously forming stars for at least 500 Myr. As the only large disk galaxy that is close enough to obtain the photometry for this type of spatially-resolved SFH mapping, M31 plays an important role in our understanding of the evolution of an L* galaxy.

scholarly journals From spirals to lenticulars: Evidence from the rotation curves and mass models of three early-type galaxies

2020 ◽  
Vol 641 ◽  
pp. A31
Author(s):  
A. Shelest ◽  
F. Lelli
Keyword(s):  
High Mass ◽  
Early Type ◽  
Rotation Curves ◽  
Radial Acceleration ◽  
Halo Structure ◽  
Lenticular Galaxies ◽  
Star Forming ◽  
Major Merger ◽  
Universal Law ◽  
Inner Parts

Rotation curves have traditionally been difficult to trace for early-type galaxies (ETGs) because they often lack a high-density disk of cold gas as in late-type galaxies (LTGs). In this work, we derive rotation curves for three lenticular galaxies from the ATLAS3D survey, combining CO data in the inner parts with deep HI data in the outer regions, extending out to 10−20 effective radii. We also use Spitzer photometry at 3.6 μm to decompose the rotation curves into the contributions of baryons and dark matter (DM). We find that (1) the rotation-curve shapes of these ETGs are similar to those of LTGs of a similar mass and surface brightness; (2) the dynamically-inferred stellar mass-to-light ratios are small for quiescent ETGs but similar to those of star-forming LTGs; (3) the DM halos follow the same scaling relations with galaxy luminosity as those of LTGs; and (4) one galaxy (NGC 3626) is poorly fit by cuspy DM profiles, suggesting that DM cores may exist in high-mass galaxies too. Our results indicate that these lenticular galaxies have recently transitioned from LTGs to ETGs without altering their DM halo structure (e.g., via a major merger), and they could be faded spirals. We also confirm that ETGs follow the same radial acceleration relation as LTGs, reinforcing the notion that this is a universal law for all galaxy types.

scholarly journals Case Studies of Mass Transfer and Star Formation in Galaxy Collisions

2004 ◽  
Vol 217 ◽  
pp. 400-405
Author(s):  
Curtis Struck
Keyword(s):  
Mass Transfer ◽  
Star Formation ◽  
Case Studies ◽  
Structural Parameters ◽  
Dynamical Models ◽  
Star Forming ◽  
Star Forming Regions ◽  
Individual Star ◽  
Galaxy Collisions

The amount, timing and ultimate location of mass transfer and induced star formation in galaxy collisions are sensitive functions of orbital and galaxy structural parameters. I discuss the role of detailed case studies and describe the results for two systems, Arp 284 and NGC 2207/IC 2163, that have been studied with both multiwaveband observations, and detailed dynamical models. The models yield the mass transfer and compressional histories of the encounters and the “probable causes” or triggers of individual star-forming regions.

Observations of individual star-forming regions in the nucleus of M33

1988 ◽  
Vol 333 ◽  
pp. 611 ◽  
Author(s):  
Christine D. Wilson ◽  
Nick Scoville ◽  
Barry F. Madore ◽  
D. B. Sanders ◽  
Wendy L. Freedman
Keyword(s):  
Star Forming ◽  
Star Forming Regions ◽  
Individual Star

scholarly journals PN populations in the local group and distant stellar populations

2015 ◽  
Vol 11 (S317) ◽  
pp. 83-90
Author(s):  
Warren Reid
Keyword(s):  
Interstellar Medium ◽  
Local Group ◽  
Stellar Populations ◽  
Evolutionary Information ◽  
Mass Relation ◽  
Halo Structure ◽  
Star Forming ◽  
Star Forming Regions ◽  
Luminosity Functions ◽  
Large Telescopes

AbstractOur understanding of galactic structure and evolution is far from complete. Within the past twelve months we have learnt that the Milky Way is about 50% wider than was previously thought. As a consequence, new models are being developed that force us to reassess the kinematic structure of our Galaxy. Similarly, we need to take a fresh look at the halo structure of external galaxies in our Local Group. Studies of stellar populations, star-forming regions, clusters, the interstellar medium, elemental abundances and late stellar evolution are all required in order to understand how galactic assembly has occurred as we see it. PNe play an important role in this investigation by providing a measure of stellar age, mass, abundances, morphology, kinematics and synthesized matter that is returned to the interstellar medium (ISM). Through a method of chemical tagging, halo PNe can reveal evidence of stellar migration and galactic mergers. This is an outline of the advances that have been made towards uncovering the full number of PNe in our Local Group galaxies and beyond. Current numbers are presented and compared to total population estimates based on galactic mass and luminosity. A near complete census of PNe is crucial to understanding the initial-to-final mass relation for stars with mass >1 to <8 times the mass of the sun. It also allows us to extract more evolutionary information from luminosity functions and compare dust-to-gas ratios from PNe in different galactic locations. With new data provided by the Gaia satellite, space-based telescopes and the rise of giant and extra-large telescopes, we are on the verge of observing and understanding objects such as PNe in distant galaxies with the same detail we expected from Galactic observations only a decade ago.

scholarly journals Impact of relativistic jets on the star formation rate: A turbulence-regulated framework

2021 ◽  
Author(s):  
Ankush Mandal ◽  
Dipanjan Mukherjee ◽  
Christoph Federrath ◽  
Nicole P H Nesvadba ◽  
Geoffrey V Bicknell ◽  
...  
Keyword(s):  
Star Formation ◽  
Velocity Dispersion ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Star Forming ◽  
Radio Jets ◽  
Star Formation Activity ◽  
The Galaxy ◽  
Individual Star ◽  
The Impact

Abstract We apply a turbulence-regulated model of star formation to calculate the star formation rate (SFR) of dense star-forming clouds in simulations of jet-ISM interactions. The method isolates individual clumps and accounts for the impact of virial parameter and Mach number of the clumps on the star formation activity. This improves upon other estimates of the SFR in simulations of jet–ISM interactions, which are often solely based on local gas density, neglecting the impact of turbulence. We apply this framework to the results of a suite of jet-ISM interaction simulations to study how the jet regulates the SFR both globally and on the scale of individual star-forming clouds. We find that the jet strongly affects the multi-phase ISM in the galaxy, inducing turbulence and increasing the velocity dispersion within the clouds. This causes a global reduction in the SFR compared to a simulation without a jet. The shocks driven into clouds by the jet also compress the gas to higher densities, resulting in local enhancements of the SFR. However, the velocity dispersion in such clouds is also comparably high, which results in a lower SFR than would be observed in galaxies with similar gas mass surface densities and without powerful radio jets. We thus show that both local negative and positive jet feedback can occur in a single system during a single jet event, and that the star-formation rate in the ISM varies in a complicated manner that depends on the strength of the jet-ISM coupling and the jet break-out time-scale.

scholarly journals Circumnuclear Star Formation in Spiral Galaxies from HST Images: NGC 4314

2002 ◽  
Vol 207 ◽  
pp. 708-710
Author(s):  
Cláudia Winge ◽  
Miriani G. Pastoriza
Keyword(s):  
Stellar Population ◽  
Spiral Galaxies ◽  
Broad Band ◽  
Nearby Galaxy ◽  
Ellipse Fitting ◽  
Star Forming ◽  
Star Forming Regions ◽  
First Results ◽  
Individual Star ◽  
The Individual

The first results of a study of the circumnuclear star-forming regions in HST broad band images of the nearby galaxy NGC4314 are presented. After modeling the bulge stellar population using ellipse fitting and subtracting the resulting model from the original images, aperture photometry of the individual star-forming regions in the ring was performed. For a total of 75 regions detected 3σ above the background, we obtained mean colors (f439—f569) = −0.72 ± 0.27, and (f569—f814) = −0.69 ± 0.35, with the NW regions being ∼ 0.5 mag bluer in both colors than the NE ones, an effect that may be caused by internal reddening.

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