scholarly journals Spatially resolved dynamics of high-z star forming galaxies

2008 ◽  
Vol 4 (S254) ◽  
pp. 33-34
Author(s):  
Reinhard Genzel
Keyword(s):  
Star Formation ◽  
Galaxy Evolution ◽  
Adaptive Optics ◽  
Disk Galaxies ◽  
Massive Galaxies ◽  
Star Forming ◽  
Secular Evolution ◽  
Spatially Resolved ◽  
The Impact ◽  
Integral Field

AbstractI report on two major programs to study the kinematic properties of galaxies at z ~ 1.5 − 3 with spatially resolved spectroscopy for the first time. Using the adaptive optics assisted, integral field spectrometer SINFONI on the ESO VLT, we have observed more than 70 galaxies and find compelling evidence for large, geometrically thick (turbulent), rotating disk galaxies in a majority of the objects that we can spatially resolve. It appears that these star forming disks are driven by continuous, rapid accretion of gas from their dark matter halos, and that their evolution is strongly influenced by internal, secular evolution. In contrast to the 20 submillimeter galaxies that we have investigated with the IRAM Plateau de Bure millimetre interferometer we find strong evidence for compact, major mergers. I discuss the impact of these new observations on our understanding of galaxy evolution in the early Universe.For the SINS survey we have carried out Hα integral field spectroscopy of well-resolved, UV/optically selected star-forming galaxies at z ~ 2 with SINFONI on the ESO VLT. The SINS sample is representative of the majority of massive (M* > a few 1010M⊙) star-forming galaxies at that redshift. Our data obtained with laser guide star assisted adaptive optics in good seeing show the presence of turbulent, rotating star-forming rings/disks in at least a third of the sample, plus central bulge/inner disk components in some of the best cases, whose mass fractions relative to total dynamical mass appears to scale with [NII]/Hα flux ratio and ‘star formation’ age. Another third of the SINS galaxies show clear signs of kinematic perturbations by a merger, while the last third appear to be compact, ‘dispersion’ limited systems.Our interpretation of these data is that the buildup of the central disks and bulges of massive galaxies at z ~ 2 can be driven by the early secular evolution of gas-rich ‘proto’-disks. High-redshift disks exhibit large random motions. This turbulence may in part be stirred up by the release of gravitational energy in the rapid ‘cold’ accretion flows along the filaments of the cosmic web. As a result, dynamical friction and viscous processes proceed on a time scale of < 1 Gyr, at least an order of magnitude faster than in disk galaxies at z ~ 0. Early secular evolution thus drives gas and stars into the central regions and can build up exponential disks and massive bulges, even without major mergers. Secular evolution along with increased efficiency of star formation at high surface densities may also help to account for the short time scales of the stellar buildup observed in massive galaxies at z ~ 2.

scholarly journals Star-Forming Galaxies at Cosmic Noon

2020 ◽  
Vol 58 (1) ◽  
pp. 661-725 ◽  
Author(s):  
Natascha M. Förster Schreiber ◽  
Stijn Wuyts
Keyword(s):  
Star Formation ◽  
Galaxy Evolution ◽  
Star Formation History ◽  
Massive Galaxies ◽  
Star Forming ◽  
Dense Cores ◽  
Gravitational Instabilities ◽  
James Webb Space Telescope ◽  
Formation History ◽  
Large Telescopes

Ever deeper and wider look-back surveys have led to a fairly robust outline of the cosmic star-formation history, which culminated around [Formula: see text]; this period is often nicknamed “cosmic noon.” Our knowledge about star-forming galaxies at these epochs has dramatically advanced from increasingly complete population censuses and detailed views of individual galaxies. We highlight some of the key observational insights that influenced our current understanding of galaxy evolution in the equilibrium growth picture: ▪  Scaling relations between galaxy properties are fairly well established among massive galaxies at least out to [Formula: see text], pointing to regulating mechanisms already acting on galaxy growth. ▪  Resolved views reveal that gravitational instabilities and efficient secular processes within the gas- and baryon-rich galaxies at [Formula: see text] play an important role in the early buildup of galactic structure. ▪  Ever more sensitive observations of kinematics at [Formula: see text] are probing the baryon and dark matter budget on galactic scales and the links between star-forming galaxies and their likely descendants. ▪  Toward higher masses, massive bulges, dense cores, and powerful AGNs and AGN-driven outflows are more prevalent and likely play a role in quenching star formation. We outline emerging questions and exciting prospects for the next decade with upcoming instrumentation, including the James Webb Space Telescope and the next generation of extremely large telescopes.

scholarly journals Spatially-resolved SFR in nearby disk galaxies using IFS data

2016 ◽  
Vol 11 (S321) ◽  
pp. 273-273
Author(s):  
C. Catalán-Torrecilla ◽  
A. Gil de Paz ◽  
A. Castillo-Morales ◽  
J. Méndez-Abreu ◽  
S. Pascual ◽  
...  
Keyword(s):  
Star Formation ◽  
Spatial Information ◽  
Formation Rate ◽  
Cosmic Time ◽  
Stellar Mass ◽  
Massive Galaxies ◽  
Star Forming ◽  
Spatially Resolved ◽  
Open Questions ◽  
Stellar Masses

AbstractExploring the spatial distribution of the star formation rate (SFR) in nearby galaxies is essential to understand their evolution through cosmic time. With this aim in mind, we use a representative sample that contains a variety of morphological types, the CALIFA Integral Field Spectroscopy (IFS) sample. Previous to this work, we have verified that our extinction-corrected Hα measurements successfully reproduce the values derived from other SFR tracers such as Hαobs + IR or UVobs + IR (Catalán-Torrecilla et al. 2015).Now, we go one step further applying 2-dimensional photometric decompositions (Méndez-Abreu et al. (2008), Méndez-Abreu et al. (2014)) over these datacubes. This method allows us to obtain the amount of SFR in the central part (bulge or nuclear source), the bar and the disk, separately. First, we determine the light coming from each component as the ratio between the luminosity in every component (bulge, bar or disk) and the total luminosity of the galaxy. Then, for each galaxy we multiply the IFS datacubes by these previous factors to recover the luminosity in each component. Finally, we derive the spectrum associated to each galaxy component integrating the spatial information in the weighted datacube using an elliptical aperture covering the whole galaxy.2D photometric decomposition applied over 3D datacubes will give us a more detailed understanding of the role that disks play in more massive galaxies. Knowing if the disks in more massive SF galaxies have on average a lower or higher level of star formation activity and how these results are affected by the presence of nuclear bars are still open questions that we can now solve. We describe the behavior of these components in the SFR vs. stellar mass diagram. In particular, we highlight the role of the disks and their contribution to both the integrated SFR for the whole galaxy and the SFR in the disk at different stellar masses in the SFR vs. stellar mass diagram together with their relative position to the star forming Main Sequence.

High-redshift starbursts as progenitors of massive galaxies

2020 ◽  
Vol 15 (S359) ◽  
pp. 22-26
Author(s):  
Carlos Gómez-Guijarro
Keyword(s):  
Star Formation ◽  
Compact Star ◽  
High Redshift ◽  
Stellar Mass ◽  
Starburst Galaxies ◽  
The Other ◽  
Massive Galaxies ◽  
Star Forming ◽  
Spatially Resolved ◽  
Minor Mergers

AbstractStarbursting dust-rich galaxies are capable of assembling large amounts of stellar mass very quickly. They have been proposed as progenitors of the population of compact massive quiescent galaxies at z ˜ 2. To test this connection, we present a detailed spatially-resolved study of the stars, dust, and stellar mass in a sample of six submillimeter-bright starburst galaxies at z ˜ 4.5. We found that the systems are undergoing minor mergers and the bulk star formation is located in extremely compact regions. On the other hand, optically-compact star forming galaxies have also been proposed as immediate progenitors of compact massive quiescent galaxies. Were they formed in slow secular processes or in rapid merger-driven starbursts? We explored the location of galaxies with respect to star-forming and structural relations and study the burstiness of star formation. Our results suggest that compact star-forming galaxies could be starbursts winding down and eventually becoming quiescent.

scholarly journals J-PLUS: Impact of bars on quenching timescales in nearby green valley disc galaxies

2019 ◽  
Vol 630 ◽  
pp. A88
Author(s):  
J. P. Nogueira-Cavalcante ◽  
R. Dupke ◽  
P. Coelho ◽  
M. L. L. Dantas ◽  
T. S. Gonçalves ◽  
...  
Keyword(s):  
Star Formation ◽  
Galaxy Evolution ◽  
Clear Correlation ◽  
Spectral Indices ◽  
Local Universe ◽  
Star Forming ◽  
Magnitude Diagram ◽  
Star Formation Histories ◽  
The Impact ◽  
Disc Galaxies

Context. Between the blue cloud and the red sequence peaks on the galaxy colour–magnitude diagram there is a region sparsely populated by galaxies called the green valley. In a framework where galaxies mostly migrate on the colour–magnitude diagram from star forming to quiescent, the green valley is considered a transitional galaxy stage. The details of the processes that drive galaxies from star-forming to passive systems still remain unknown. Aims. We aim to measure the transitional timescales of nearby galaxies across the green valley, through the analysis of Galaxy Evolution Explorer and Javalambre Photometric of Local Universe Survey photometric data. Specifically, we seek to study the impact of bars on the quenching timescales. Methods. We developed a method that estimates empirically the star formation quenching timescales of green valley galaxies, assuming an exponential decay model of the star formation histories and through a combination of narrow and broad bands from the Javalambre Photometric of Local Universe Survey and Galaxy Evolution Explorer. We correlated these quenching timescales with the presence of bars. Results. We find that the Javalambre Photometric of Local Universe Survey colours F0395 −g and F0410 −g are sensitive to different star formation histories, showing, consequently, a clear correlation with the Dn(4000) and Hδ, A spectral indices. We measured quenching timescales based on these colours and we find that quenching timescales obtained with our new approach are in agreement with those determined using spectral indices. We also compared the quenching timescales of green valley disc galaxies as a function of the probability of hosting a bar. We find that galaxies with high bar probability tend to quench their star formation slowly. Conclusions. We conclude that: (1) Javalambre Photometric of Local Universe Survey filters can be used to measure quenching timescales in nearby green valley galaxies; and (2) the resulting star formation quenching timescales are longer for barred green valley galaxies. Considering that the presence of a bar indicates that more violent processes (e.g. major mergers) are absent in host galaxies, we conclude that the presence of a bar can be used as a morphological signature for slow star formation quenching.

scholarly journals The impact of AGN on stellar kinematics and orbits in simulated massive galaxies

2019 ◽  
Vol 489 (2) ◽  
pp. 2702-2722 ◽  
Author(s):  
Matteo Frigo ◽  
Thorsten Naab ◽  
Michaela Hirschmann ◽  
Ena Choi ◽  
Rachel S Somerville ◽  
...  
Keyword(s):  
Star Formation ◽  
High Redshift ◽  
Stellar Kinematics ◽  
Global Parameter ◽  
Stellar Orbits ◽  
Massive Galaxies ◽  
Field Unit ◽  
The Impact ◽  
Integral Field

ABSTRACT We present a series of 10 × 2 cosmological zoom simulations of the formation of massive galaxies with and without a model for active galactic nucleus (AGN) feedback. Differences in stellar population and kinematic properties are evaluated by constructing mock integral field unit maps. The impact of the AGN is weak at high redshift when all systems are mostly fast rotating and disc-like. After z ∼ 1 the AGN simulations result in lower mass, older, less metal rich, and slower rotating systems with less discy isophotes – in general agreement with observations. 2D kinematic maps of in situ and accreted stars show that these differences result from reduced in-situ star formation due to AGN feedback. A full analysis of stellar orbits indicates that galaxies simulated with AGN are typically more triaxial and have higher fractions of x-tubes and box orbits and lower fractions of z-tubes. This trend can also be explained by reduced late in-situ star formation. We introduce a global parameter, ξ3, to characterize the anticorrelation between the third-order kinematic moment h3 and the line-of-sight velocity (Vavg/σ), and compare to ATLAS3D observations. The kinematic correlation parameter ξ3 might be a useful diagnostic for large integral field surveys as it is a kinematic indicator for intrinsic shape and orbital content.

scholarly journals Cosmological simulations of the same spiral galaxy: the impact of baryonic physics

2020 ◽  
Vol 501 (1) ◽  
pp. 62-77
Author(s):  
A Nuñez-Castiñeyra ◽  
E Nezri ◽  
J Devriendt ◽  
R Teyssier
Keyword(s):  
Star Formation ◽  
Galaxy Evolution ◽  
Galaxy Formation ◽  
Spiral Galaxy ◽  
Milky Way ◽  
Spiral Galaxies ◽  
Cosmological Simulations ◽  
Star Forming ◽  
Small Scales ◽  
The Impact

ABSTRACT The interplay of star formation (SF) and supernova (SN) feedback in galaxy formation is a key element for understanding galaxy evolution. Since these processes occur at small scales, it is necessary to have sub-grid models that recover their evolution and environmental effects at the scales reached by cosmological simulations. In this work, we present the results of the Mochima simulation, where we simulate the same spiral galaxy inhabiting a Milky Way (MW) size halo in a cosmological environment changing the sub-grid models for SN feedback and SF. We test combinations of the Schmidt law and a multifreefall based SF with delayed cooling feedback or mechanical feedback. We reach a resolution of 35 pc in a zoom-in box of 36 Mpc. For this, we use the code $\rm{\small RAMSES}$ with the implementation of gas turbulence in time and trace the local hydrodynamical features of the star-forming gas. Finally, we compare the galaxies at redshift 0 with global and interstellar medium observations in the MW and local spiral galaxies. The simulations show successful comparisons with observations. Nevertheless, diverse galactic morphologies are obtained from different numerical implementations. We highlight the importance of detailed modelling of the SF and feedback processes, especially for simulations with a resolution that start to reach scales relevant for molecular cloud physics. Future improvements could alleviate the degeneracies exhibited in our simulated galaxies under different sub-grid models.

scholarly journals SDSS-IV MaNGA: spatially resolved star formation in barred galaxies

2020 ◽  
Vol 495 (4) ◽  
pp. 4158-4169 ◽  
Author(s):  
Amelia Fraser-McKelvie ◽  
Alfonso Aragón-Salamanca ◽  
Michael Merrifield ◽  
Karen Masters ◽  
Preethi Nair ◽  
...  
Keyword(s):  
Star Formation ◽  
Galaxy Evolution ◽  
Leading Edge ◽  
Host Galaxy ◽  
Massive Galaxies ◽  
Barred Galaxies ◽  
Spatially Resolved ◽  
Wide Range ◽  
Nearby Galaxies ◽  
Low Mass

ABSTRACT Bars inhabit the majority of local-Universe disc galaxies and may be important drivers of galaxy evolution through the redistribution of gas and angular momentum within discs. We investigate the star formation and gas properties of bars in galaxies spanning a wide range of masses, environments, and star formation rates using the Mapping Nearby Galaxies at APO galaxy survey. Using a robustly defined sample of 684 barred galaxies, we find that fractional (or scaled) bar length correlates with the host’s offset from the star formation main sequence. Considering the morphology of the Hα emission we separate barred galaxies into different categories, including barred, ringed, and central configurations, together with Hα detected at the ends of a bar. We find that only low-mass galaxies host star formation along their bars, and that this is located predominantly at the leading edge of the bar itself. Our results are supported by recent simulations of massive galaxies, which show that the position of star formation within a bar is regulated by a combination of shear forces, turbulence, and gas flows. We conclude that the physical properties of a bar are mostly governed by the existing stellar mass of the host galaxy, but that they also play an important role in the galaxy’s ongoing star formation.

scholarly journals Inner and outer star forming regions over the discs of spiral galaxies I. Sample characterization

2016 ◽  
Vol 11 (S321) ◽  
pp. 296-296
Author(s):  
Marina Rodríguez-Baras ◽  
A.I. Díaz ◽  
F.F. Rosales-Ortega
Keyword(s):  
Star Formation ◽  
Disk Galaxies ◽  
Work Sample ◽  
Star Forming ◽  
Star Forming Regions ◽  
Integral Field Spectroscopy ◽  
The Galaxy ◽  
Sample Characterization ◽  
Integral Field

AbstractThis project is aimed at understanding the dependence of star formation on the environment by analysing young stellar populations in two very different positions in disk galaxies: circumnuclear and outer disk giant regions. Integral field spectroscopy (IFS) provide an ideal means to achieve these goals providing simultaneous spatial and spectral resolution. Here we present the characterization of the work sample, composed by 671 outer regions and 725 inner regions from 263 isolated spirals galaxies observed by the CALIFA survey. The wide number of regions in both samples allows us to obtain statistically relevant results about the influence of metallicity, density and environment on star formation, and how it disseminates over the galaxy, to obtain evolutionary stories for the star-forming regions and to compare our results with models of massive star formation and galactic chemical evolution.

scholarly journals SDSS-IV MaNGA: The kinematic-morphology of galaxies on the mass versus star-formation relation in different environments

2020 ◽  
Vol 495 (2) ◽  
pp. 1958-1977 ◽  
Author(s):  
Bitao Wang ◽  
Michele Cappellari ◽  
Yingjie Peng ◽  
Mark Graham
Keyword(s):  
Star Formation ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Stellar Mass ◽  
Early Type ◽  
Stellar Kinematics ◽  
Massive Galaxies ◽  
Star Forming ◽  
Integral Field ◽  
Environmental Dependence

ABSTRACT We study the link between the kinematic-morphology of galaxies, as inferred from integral-field stellar kinematics, and their relation between mass and star formation rate. Our sample consists of ∼3200 galaxies with integral-field spectroscopic data from the MaNGA survey (Mapping Nearby Galaxies at Apache Point Observatory) with available determinations of their effective stellar angular momentum within the half-light radius $\lambda _{R_e}$. We find that for star-forming galaxies, namely along the star formation main sequence (SFMS), the $\lambda _{R_e}$ values remain large and almost unchanged over about two orders of magnitude in stellar mass, with the exception of the lowest masses $\mathcal {M}_{\star }\lesssim 2\times 10^{9} \, \mathcal {M}_{\odot }$, where $\lambda _{R_e}$ slightly decreases. The SFMS is dominated by spiral galaxies with small bulges. Below the SFMS, but above the characteristic stellar mass $\mathcal {M}_{\rm crit}\approx 2\times 10^{11} \, \mathcal {M}_{\odot }$, there is a sharp decrease in $\lambda _{R_e}$ with decreasing star formation rate (SFR): massive galaxies well below the SFMS are mainly slow-rotator early-type galaxies, namely genuinely spheroidal galaxies without discs. Below the SFMS and below $\mathcal {M}_{\rm crit}$ the decrease of $\lambda _{R_e}$ with decreasing SFR becomes modest or nearly absent: low-mass galaxies well below the SFMS, are fast-rotator early-type galaxies, and contain fast-rotating stellar discs like their star-forming counterparts. We also find a small but clear environmental dependence for the massive galaxies: in the mass range $10^{10.9}\!-\!10^{11.5} \, \mathcal {M}_{\odot }$, galaxies in rich groups or denser regions or classified as central galaxies have lower values of $\lambda _{R_e}$. While no environmental dependence is found for galaxies of lower mass. We discuss how the above results can be understood as due to the different star formation and mass assembly histories of galaxies with varying mass.

scholarly journals Emission-Line Diagnostics for Galaxies

2015 ◽  
Vol 11 (A29B) ◽  
pp. 264-264
Author(s):  
Lisa J. Kewley
Keyword(s):  
Star Formation ◽  
Emission Line ◽  
Power Sources ◽  
Star Forming ◽  
Spatially Resolved ◽  
Integral Field Spectroscopy ◽  
Field Spectroscopy ◽  
Yield Information ◽  
Ir Diagnostics ◽  
Integral Field

AbstractI will give an overview of the emission-line diagnostics used for star-forming galaxies. I will review the UV, optical, and IR diagnostics that can be used to yield information about the ISM conditions, star-formation properties, and power sources in GRB hosts, both globally, and with spatially-resolved data. I will discuss wide integral field spectroscopy and AO-led integral field spectroscopy on current and future telescopes, focusing on the insights to be gained on the properties of GRB sites.

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