scholarly journals What Is the Role of Stellar Radiative Feedback in Setting the Stellar Mass Spectrum?

2020 ◽  
Vol 904 (2) ◽  
pp. 194
Author(s):  
Patrick Hennebelle ◽  
Benoît Commerçon ◽  
Yueh-Ning Lee ◽  
Gilles Chabrier
Keyword(s):  
Mass Spectrum ◽  
Stellar Mass ◽  
Radiative Feedback

scholarly journals The role of mergers and interactions in driving the evolution of dwarf galaxies over cosmic time

2020 ◽  
Vol 500 (4) ◽  
pp. 4937-4957 ◽  
Author(s):  
G Martin ◽  
R A Jackson ◽  
S Kaviraj ◽  
H Choi ◽  
J E G Devriendt ◽  
...  
Keyword(s):  
Star Formation ◽  
Dwarf Galaxies ◽  
Large Fraction ◽  
Structural Evolution ◽  
Cosmic Time ◽  
Stellar Mass ◽  
High Mass ◽  
Key Drivers ◽  
Mass Assembly

ABSTRACT Dwarf galaxies (M⋆ < 109 M⊙) are key drivers of mass assembly in high-mass galaxies, but relatively little is understood about the assembly of dwarf galaxies themselves. Using the NewHorizon cosmological simulation (∼40 pc spatial resolution), we investigate how mergers and fly-bys drive the mass assembly and structural evolution of around 1000 field and group dwarfs up to z = 0.5. We find that, while dwarf galaxies often exhibit disturbed morphologies (5 and 20 per cent are disturbed at z = 1 and z = 3 respectively), only a small proportion of the morphological disturbances seen in dwarf galaxies are driven by mergers at any redshift (for 109 M⊙, mergers drive under 20 per cent morphological disturbances). They are instead primarily the result of interactions that do not end in a merger (e.g. fly-bys). Given the large fraction of apparently morphologically disturbed dwarf galaxies which are not, in fact, merging, this finding is particularly important to future studies identifying dwarf mergers and post-mergers morphologically at intermediate and high redshifts. Dwarfs typically undergo one major and one minor merger between z = 5 and z = 0.5, accounting for 10 per cent of their total stellar mass. Mergers can also drive moderate star formation enhancements at lower redshifts (3 or 4 times at z = 1), but this accounts for only a few per cent of stellar mass in the dwarf regime given their infrequency. Non-merger interactions drive significantly smaller star formation enhancements (around two times), but their preponderance relative to mergers means they account for around 10 per cent of stellar mass formed in the dwarf regime.

scholarly journals The less significant role of large-scale environment than optical AGN in nearby, isolated elliptical galaxies

2018 ◽  
Vol 620 ◽  
pp. A117 ◽  
Author(s):  
I. Lacerna ◽  
M. Argudo-Fernández ◽  
S. Duarte Puertas
Keyword(s):  
Large Scale ◽  
Formation Rate ◽  
Elliptical Galaxies ◽  
Stellar Mass ◽  
Mass Scale ◽  
Strength Parameter ◽  
Primary Role ◽  
Isolated Galaxies ◽  
Low Mass

Context. The formation and evolution of elliptical galaxies in low-density environments are less understood than classical elliptical galaxies in high-density environments. Isolated galaxies are defined as galaxies without massive neighbors within scales of galaxy groups. The effect of the environment at several Mpc scales on their properties has been barely explored. We study the role of the large-scale environment in 573 isolated elliptical galaxies out to z = 0.08. Aims. We aim to explore whether the large-scale environment affects some of the physical properties of the isolated galaxies studied in this work. Methods. We used three environmental estimators of the large-scale structure within a projected radius of 5 Mpc around isolated galaxies: the tidal strength parameter, projected density ηk,LSS, and distance to the fifth nearest neighbor galaxy. We studied isolated galaxies regarding stellar mass, integrated optical g − i color, specific star formation rate (sSFR), and emission lines. Results. We find 80% of galaxies at lower densities correspond to “red and dead” elliptical galaxies. Blue and red galaxies do not tend to be located in different environments according to ηk,LSS. Almost all the isolated ellipticals in the densest large-scale environments are red or quenched, of which a third are low-mass galaxies. The percentage of isolated elliptical galaxies located in the active galactic nucleus (AGN) region of the BPT diagram is 64%. We identified 33 blue, star-forming (SF) isolated ellipticals using both color and sSFR. Half of these are SF nuclei in the BPT diagram, which amounts to 5% of the galaxies in this diagram. Conclusions. The large-scale environment does not play the primary role in determining the color or sSFR of isolated elliptical galaxies. The large-scale environment seems to be negligible from a stellar mass scale around 1010.6 M⊙, probably because of the dominant presence of AGN at higher masses. For lower masses, the processes of cooling and infall of gas from large scales are very inefficient in ellipticals. Active galactic nuclei might also be an essential ingredient to keep most of the low-mass isolated elliptical galaxies quenched.

On Coagulation and the Stellar Mass Spectrum

1995 ◽  
Vol 452 ◽  
pp. 652 ◽  
Author(s):  
Eric J. Allen ◽  
Pierre Bastien
Keyword(s):  
Mass Spectrum ◽  
Stellar Mass

scholarly journals xGASS: the role of bulges along and across the local star-forming main sequence

2020 ◽  
Vol 493 (4) ◽  
pp. 5596-5605 ◽  
Author(s):  
Robin H W Cook ◽  
Luca Cortese ◽  
Barbara Catinella ◽  
Aaron Robotham
Keyword(s):  
Star Formation ◽  
Main Sequence ◽  
Formation Rate ◽  
Stellar Mass ◽  
Local Universe ◽  
Star Forming ◽  
Star Formation Activity ◽  
The Galaxy ◽  
Stellar Masses

ABSTRACT We use our catalogue of structural decomposition measurements for the extended GALEX Arecibo SDSS Survey (xGASS) to study the role of bulges both along and across the galaxy star-forming main sequence (SFMS). We show that the slope in the sSFR–M⋆ relation flattens by ∼0.1 dex per decade in M⋆ when re-normalizing specifice star formation rate (sSFR) by disc stellar mass instead of total stellar mass. However, recasting the sSFR–M⋆ relation into the framework of only disc-specific quantities shows that a residual trend remains against disc stellar mass with equivalent slope and comparable scatter to that of the total galaxy relation. This suggests that the residual declining slope of the SFMS is intrinsic to the disc components of galaxies. We further investigate the distribution of bulge-to-total ratios (B/T) as a function of distance from the SFMS (ΔSFRMS). At all stellar masses, the average B/T of local galaxies decreases monotonically with increasing ΔSFRMS. Contrary to previous works, we find that the upper envelope of the SFMS is not dominated by objects with a significant bulge component. This rules out a scenario in which, in the local Universe, objects with increased star formation activity are simultaneously experiencing a significant bulge growth. We suggest that much of the discrepancies between different works studying the role of bulges originate from differences in the methodology of structurally decomposing galaxies.

scholarly journals Observational evidence for stellar-mass black holes

2006 ◽  
Vol 2 (S238) ◽  
pp. 3-12 ◽  
Author(s):  
Jorge Casares
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Mass Spectrum ◽  
Radial Velocity ◽  
Stellar Mass ◽  
Observational Evidence ◽  
X Ray ◽  
History Of ◽  
X Ray Binaries ◽  
Dynamical Masses

AbstractRadial velocity studies of X-ray binaries provide the most solid evidence for the existence of stellar-mass black holes. We currently have 20 confirmed cases, with dynamical masses in excess of 3 M⊙. Accurate masses have been obtained for a subset of systems which gives us a hint at the mass spectrum of the black hole population. This review summarizes the history of black hole discoveries and presents the latest results in the field.

scholarly journals Galaxy kinematics across different environments in the RXJ1347−1145 cluster complex

2020 ◽  
Vol 637 ◽  
pp. A30
Author(s):  
J. M. Pérez-Martínez ◽  
B. Ziegler ◽  
A. Böhm ◽  
M. Verdugo
Keyword(s):  
Star Formation ◽  
Galaxy Evolution ◽  
Formation Rate ◽  
Stellar Mass ◽  
Cluster Complex ◽  
Mass Relation ◽  
Cluster Membership ◽  
Cluster Galaxies ◽  
Fisher Relation

Aims. In order to understand the role of the different processes that drive galaxy evolution in clusters, we need comprehensive studies that simultaneously examine several of the most important physical properties of galaxies. In this work we study the interplay between the kinematic state and star formation activity of galaxies in the RXJ1347−1145 cluster complex at z ∼ 0.45. Methods. We used VLT/VIMOS to obtain slit spectra for 95 galaxies across the 40′ × 40′ area where the RXJ1347−1145 cluster complex resides. We determined the cluster membership of our targets by identifying one or more of the available emission lines within the wavelength range. Our spectroscopy is complemented with archival SUBARU/Suprime-Cam deep photometric observations in five optical bands (B, V, Rc, Ic, z′). We examined the kinematic properties of our sample attending to the degree of distortion of the extracted rotation curves. Regular rotating galaxies were included in our Tully–Fisher analysis while the distorted ones were used to study the role of cluster-specific interactions with respect to star formation and AGN activity. Results. Our analysis confirmed the cluster membership for approximately half of our targets. We report a higher fraction of galaxies with irregular gas kinematics in the cluster environment than in the field. Cluster galaxies with regular rotation display a moderate brightening in the B-band Tully–Fisher relation compatible with the gradual evolution of the stellar populations with lookback time, and no significant evolution in the stellar-mass Tully–Fisher relation, in line with previous studies at similar redshift. Average specific star formation rate values are slightly lower in our cluster sample (−0.15 dex) with respect to the main sequence of star-forming galaxies, confirming the role of the environment in the early quenching of star formation in clusters. Finally, we carried out an exploratory observational study on the stellar-to-halo mass relation finding that cluster galaxies tend to have slightly lower stellar mass values for a fixed halo mass compared to their field counterparts.

scholarly journals Ultralight bosons for strong gravity applications from simple Standard Model extensions

2021 ◽  
Vol 2021 (12) ◽  
pp. 047
Author(s):  
Felipe F. Freitas ◽  
Carlos A.R. Herdeiro ◽  
António P. Morais ◽  
António Onofre ◽  
Roman Pasechnik ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Mass Spectrum ◽  
Standard Model ◽  
Symmetry Breaking ◽  
Spontaneous Symmetry Breaking ◽  
Mass Range ◽  
Stellar Mass ◽  
Compact Objects ◽  
The Standard Model

Abstract We construct families, and concrete examples, of simple extensions of the Standard Model that can yield ultralight real or complex vectors or scalars with potential astrophysical relevance. Specifically, the mass range for these putative fundamental bosons (∼ 10-10-10-20 eV) would lead dynamically to both new non-black hole compact objects (bosonic stars) and new non-Kerr black holes, with masses of ∼ M⊙ to ∼ 1010 M⊙, corresponding to the mass range of astrophysical black hole candidates (from stellar mass to supermassive). For each model, we study the properties of the mass spectrum and interactions after spontaneous symmetry breaking, discuss its theoretical viability and caveats, as well as some of its potential and most relevant phenomenological implications linking them to the physics of compact objects.

scholarly journals The VANDELS survey: the role of ISM and galaxy physical properties in the escape of Lyα emission in z ∼ 3.5 star-forming galaxies

2019 ◽  
Vol 631 ◽  
pp. A19 ◽  
Author(s):  
F. Marchi ◽  
L. Pentericci ◽  
L. Guaita ◽  
M. Talia ◽  
M. Castellano ◽  
...  
Keyword(s):  
Star Formation ◽  
Physical Properties ◽  
Emission Line ◽  
Column Density ◽  
Star Formation Rate ◽  
Spectral Energy Distribution ◽  
Formation Rate ◽  
Stellar Mass ◽  
Dust Extinction

Aims. We wish to investigate the physical properties of a sample of Lyα emitting galaxies in the VANDELS survey, with particular focus on the role of kinematics and neutral hydrogen column density in the escape and spatial distribution of Lyα photons. Methods. From all the Lyα emitting galaxies in the VANDELS Data Release 2 at 3.5 ≲ z ≲ 4.5, we selected a sample of 52 galaxies that also have a precise systemic redshift determination from at least one nebular emission line (HeII or CIII]). For these galaxies, we derived different physical properties (stellar mass, age, dust extinction, and star formation rate) from spectral energy distribution (SED) fitting of the exquisite multiwavelength photometry available in the VANDELS fields, using the dedicated spectral modeling tool BEAGLE and the UV β slope from the observed photometry. We characterized the Lyα emission in terms of kinematics, equivalent width (EW), full width at half-maximum, and spatial extension and then estimated the velocity of the neutral outflowing gas. The ultra-deep VANDELS spectra (up to 80 h on-source integration) enable this for individual galaxies without the need to rely on stacks. We then investigated the correlations between the Lyα properties and the other measured properties to study how they affect the shape and intensity of Lyα emission. Results. We reproduce some of the well-known correlations between Lyα EW and stellar mass, dust extinction, and UV β slope, in the sense that the emission line appears brighter in galaxies with lower mass that are less dusty and bluer. We do not find any correlation with the SED-derived star formation rate, while we find that galaxies with brighter Lyα tend to be more compact in both UV and in Lyα. Our data reveal an interesting correlation between the Lyα velocity offset and the shift of the interstellar absorption lines with respect to the systemic redshift, observed for the first time at high redshifts: galaxies with higher interstellar medium (ISM) outflow velocities show smaller Lyα velocity shifts. We interpret this relation in the context of the shell-model scenario, where the velocity of the ISM and the HI column density contribute together in determining the Lyα kinematics. In support to our interpretation, we observe that galaxies with high HI column densities have much more extended Lyα spatial profiles; this is a sign of increased scattering. However, we do not find any evidence that the HI column density is related to any other physical properties of the galaxies, although this might be due in part to the limited range of parameters that our sample spans.

scholarly journals Radiative feedback and cosmic molecular gas: the role of different radiative sources

2016 ◽  
Vol 460 (4) ◽  
pp. 3733-3752 ◽  
Author(s):  
Umberto Maio ◽  
Margarita Petkova ◽  
Gabriella De Lucia ◽  
Stefano Borgani
Keyword(s):  
Molecular Gas ◽  
Radiative Feedback
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