scholarly journals Star Formation in Nearby Early-Type Galaxies: Mapping in UV, Optical and CO

2006 ◽  
Vol 2 (S235) ◽  
pp. 304-304
Author(s):  
M. Bureau ◽  
R. Bacon ◽  
M. Cappellari ◽  
F. Combes ◽  
R. L. Davies ◽  
...  
Keyword(s):  
Star Formation ◽  
Field Survey ◽  
Stellar Disk ◽  
Early Type ◽  
Stellar Kinematics ◽  
Direct Identification ◽  
Central Disk ◽  
Co Detection ◽  
Integral Field ◽  
Fast Rotating

AbstractThe SAURON integral-field survey reveals that small (~0.1,Re) kinematically decoupled cores (KDCs) in early-type galaxies are increasingly young toward the center and are typically found in fast-rotating galaxies, while large KDCs (~0.5 Re) have homogeneously old stars and are present in non-rotating galaxies (McDermid et al. 2006). GALEX UV imaging further allows the direct identification of regions of recent star formation (≤0.5 Gyr). In NGC 2974 for example, young stars are identified in the center and an outer ring Jeong et al. 2006). Nuclear and inner ionised-gas rings (Sarzi et al. 2006) then suggest that current star formation is bar-driven. The CO detection rate of SAURON early-type galaxies is ≈40% (Combes et al. in prep.). Synthesis imaging reveals that it is generally contained in a well-ordered central disk, both in galaxies with a (young) central stellar disk (e.g. NGC 4459, NGC 4526) or a (young) KDC (e.g. NGC 3032, NGC 4150) (Young et al. in prep.). CO also traces well the young stellar populations and ionised gas distribution and kinematics, but in KDCs not always the stellar kinematics Emsellem et al. 2004; Sarzi et al. 2006; Kuntschner et al. 2006).

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 Recent star formation in the Hi dominated outer regions of early-type galaxies

2016 ◽  
Vol 11 (S321) ◽  
pp. 279-279
Author(s):  
Mustafa K. Yıldız ◽  
Paolo Serra ◽  
Reynier F. Peletier ◽  
Tom A. Oosterloo ◽  
Pierre-Alain Duc
Keyword(s):  
Star Formation ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Radial Profile ◽  
Control Sample ◽  
Neutral Hydrogen ◽  
Stellar Mass ◽  
Early Type ◽  
Stellar Kinematics ◽  
The Impact

AbstractContextAccording to the ATLAS3D project, about 20 percent of all nearby early-type galaxies (D < 42 Mpc; MK < -21.5 mag; stellar mass Mstars ≳ 6 × 109 M⊙) outside clusters are surrounded by a disc or ring of low-column-density neutral hydrogen (Hi) gas with typical radii of tens of kpc, much larger than the stellar body.AimsOur aim is to understand the impact of these gas systems on the host galaxies, in particular, whether there is any recent star formation related to the Hi and effect of recent star formation on the host early-type galaxies.Methods and sampleWe analyse the distribution of star formation out to large radii by using resolved Hi images together with UV and optical images. We calculate the UV-UV and UV-optical colours in two apertures, 1-3 and 3-10 Reff. Using FUV emission as a proxy for star formation, we also estimate the integrated star formation rate in the outer regions. Our sample consists of 18 Hi-rich galaxies as well as 55 control galaxies where no Hi has been detected. We select the control sample galaxies to match the Hi-rich galaxies in stellar mass, environment, distance and stellar kinematics.ResultsIn half of the Hi-rich galaxies the radial UV profile changes slope at the position of the Hi radial profile peak. We find that the FUV-NUV and UV-optical colours in the first and second apertures of the Hi-rich galaxies are on average 0.5 and 0.8 mag bluer than the Hi-poor ones, respectively. We also find that the Hi-rich early-type galaxies have colour gradients that are almost 2 times stronger than the Hi-poor ones. we estimate the integrated star formation rate in the outer regions (R > 1 Reff) to be on average ~ 6.1×10−3 M⊙ yr−1 for the Hi-rich galaxies. We find that the gas depletion time in the outermost region (3-10 Reff) is ~ 80 Gyrs, which is similar to that estimated for the outskirts of spirals.ConclusionsStudying the stellar populations in early type galaxies with and without Hi, we find that galaxies with Hi generally show UV and UV-Optical colours in the outer parts that are bluer than those of early-type galaxies without Hi. This shows that the Hi is actively involved in recent star formation. The star formation rate in the outer regions is too low to build a stellar disc, and therefore change the morphology of the host even when integrated over several Gyrs. Star formation in outermost regions does not depend on the type of the galaxies.

scholarly journals The SAMI Galaxy Survey: early data release and first science

2014 ◽  
Vol 10 (S311) ◽  
pp. 104-109
Author(s):  
Scott M. Croom ◽  
James T. Allen ◽  
Luca Cortese ◽  
Lisa Fogarty ◽  
I-Ting Ho ◽  
...  
Keyword(s):  
Field Survey ◽  
Early Data ◽  
Scaling Relations ◽  
Early Type ◽  
Spatially Resolved ◽  
Galactic Winds ◽  
Data Release ◽  
Integral Field Spectrograph ◽  
Integral Field ◽  
Ongoing Project

AbstractThe Sydney–AAO Multi-object Integral field spectrograph (SAMI) Galaxy Survey is an ongoing project to obtain spatially resolved spectroscopic observations of ~3400 galaxies by mid-2016. To date, a total of ~1000 galaxies have been observed, making the SAMI Galaxy Survey the largest integral field survey in existence. In July 2014 the early data release for the SAMI galaxy Survey occurred, with over 100 galaxies available to the community. The richness of the SAMI dataset allows a vast array of science. We highlight some of the early science results from the project, including the discovery and analysis of galactic winds, the distribution of fast and slow rotating early type galaxies, and the unification of galaxy scaling relations.

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 Scaling relations in early-type galaxies from integral-field stellar kinematics

2009 ◽  
Vol 5 (H15) ◽  
pp. 81-81
Author(s):  
M. Cappellari ◽  
N. Scott ◽  
K. Alatalo ◽  
L. Blitz ◽  
M. Bois ◽  
...  
Keyword(s):  
Surface Brightness ◽  
Velocity Dispersion ◽  
Scaling Relations ◽  
Early Type ◽  
Stellar Kinematics ◽  
Fundamental Plane ◽  
The Past ◽  
Stellar Velocity ◽  
Integral Field ◽  
Significant Effort

Early-type galaxies (ETGs) satisfy a now classic scaling relation Re ∝ σ1.2eI−0.8e, the Fundamental Plane (FP; Djorgovski & Davis 1987; Dressler et al. 1987), between their size, stellar velocity dispersion and mean surface brightness. A significant effort has been devoted in the past twenty years to try to understand why the coefficients of the relation are not the ones predicted by the virial theorem Re ∝ σ2eI−1e.

scholarly journals Star formation in CALIFA early-type galaxies: a matter of discs

2019 ◽  
Vol 488 (1) ◽  
pp. L80-L84 ◽  
Author(s):  
J Méndez-Abreu ◽  
S F Sánchez ◽  
A de Lorenzo-Cáceres
Keyword(s):  
Star Formation ◽  
Main Sequence ◽  
Formation Rate ◽  
Molecular Gas ◽  
Early Type ◽  
Star Forming ◽  
Integral Field Spectroscopy ◽  
The Galaxy ◽  
First Time ◽  
Integral Field

ABSTRACT The star formation main sequence (SFMS) is a tight relation between the galaxy star formation rate (SFR) and its total stellar mass (M⋆). Early-type galaxies (ETGs) are often considered as low-SFR outliers of this relation. We study, for the first time, the separated distribution in the SFR versus M⋆ of bulges and discs of 49 ETGs from the CALIFA survey. This is achieved using c2d, a new code to perform spectrophotometric decompositions of integral field spectroscopy data cubes. Our results reflect that: (i) star formation always occurs in the disc component and not in bulges; (ii) star-forming discs in our ETGs are compatible with the SFMS defined by star-forming galaxies at z ∼ 0; (iii) the star formation is not confined to the outskirts of discs, but it is present at all radii (even where the bulge dominates the light); (iv) for a given mass, bulges exhibit lower sSFR than discs at all radii; and (v) we do not find a deficit of molecular gas in bulges with respect to discs for a given mass in our ETGs. We speculate our results favour a morphological quenching scenario for ETGs.

scholarly journals Post-starburst galaxies in SDSS-IV MaNGA

2019 ◽  
Vol 489 (4) ◽  
pp. 5709-5722 ◽  
Author(s):  
Yan-Mei Chen ◽  
Yong Shi ◽  
Vivienne Wild ◽  
Christy Tremonti ◽  
Kate Rowlands ◽  
...  
Keyword(s):  
Star Formation ◽  
Field Survey ◽  
Starburst Galaxies ◽  
Rapid Decline ◽  
Radial Profiles ◽  
Central Regions ◽  
Subsequent Quenching ◽  
Integral Field ◽  
Control Samples ◽  
Starburst Regions

ABSTRACT Post-starburst galaxies, identified by their unusually strong Balmer absorption lines and weaker than average emission lines, have traditionally been selected based on their central stellar populations. Here we identify 360 galaxies with post-starburst regions from the MaNGA integral field survey and classify these galaxies into three types: 31 galaxies with central post-starburst regions (CPSB), 37 galaxies with off-centre ring-like post-starburst regions (RPSB), and 292 galaxies with irregular post-starburst regions (IPSB). Focusing on the CPSB and RPSB samples, and comparing their radial gradients in Dn4000, HδA, and W(H α) to control samples, we find that while the CPSBs have suppressed star formation throughout their bulge and disc, and there is clear evidence of rapid decline of star formation in the central regions, the RPSBs only show clear evidence of recently rapidly suppressed star formation in their outer regions and an ongoing central starburst. The radial profiles in mass-weighted age and stellar v/σ indicate that CPSBs and RPSBs are not simply different evolutionary stages of the same event, rather the CPSB galaxies are caused by a significant disruptive event, while the RPSB galaxies are caused by disruption of gas fuelling to the outer regions. Compared to the control samples, both CPSB and RPSB galaxies show a higher fraction of interactions/mergers, misaligned gas, or bars that might be the cause of the gas inflows and subsequent quenching.

scholarly journals Modeling dark haloes in early-type galaxies: stellar kinematics at large radii

2009 ◽  
Vol 5 (H15) ◽  
pp. 69-69 ◽  
Author(s):  
Anne-Marie Weijmans
Keyword(s):  
Dark Matter ◽  
Absorption Line ◽  
New Method ◽  
Dark Matter Halo ◽  
Early Type ◽  
Stellar Kinematics ◽  
Signal To Noise ◽  
Stellar Halo ◽  
Halo Population ◽  
Integral Field

We developed a new method to obtain absorption line spectra of early-type galaxies at large radii, using integral-field spectrography (IFS). By using the spectrograph as a 'photon-collector' and adding the signal of many individual spaxels together in one spectrum, we obtain sufficient signal-to-noise to measure both stellar kinematics and line strengths at large radii. These can be used to determine the properties of the dark matter halo, as well as the stellar halo population.

scholarly journals Formation channels of slowly rotating early-type galaxies

2020 ◽  
Vol 635 ◽  
pp. A129 ◽  
Author(s):  
Davor Krajnović ◽  
Ugur Ural ◽  
Harald Kuntschner ◽  
Paul Goudfrooij ◽  
Michael Wolfe ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Surface Brightness ◽  
Element Abundance ◽  
Nuclear Surface ◽  
Formation Processes ◽  
Early Type ◽  
Stellar Kinematics ◽  
Show Evidence ◽  
Light Profiles ◽  
Integral Field

We study the evidence for a diversity of formation processes in early-type galaxies by presenting the first complete volume-limited sample of slow rotators with both integral-field kinematics from the ATLAS3D Project and high spatial resolution photometry from the Hubble Space Telescope. Analysing the nuclear surface brightness profiles of 12 newly imaged slow rotators, we classify their light profiles as core-less, and place an upper limit to the core size of about 10 pc. Considering the full magnitude and volume-limited ATLAS3D sample, we correlate the presence or lack of cores with stellar kinematics, including the proxy for the stellar angular momentum (λRe) and the velocity dispersion within one half-light radius (σe), stellar mass, stellar age, α-element abundance, and age and metallicity gradients. More than half of the slow rotators have core-less light profiles, and they are all less massive than 1011 M⊙. Core-less slow rotators show evidence for counter-rotating flattened structures, have steeper metallicity gradients, and a larger dispersion of gradient values (Δ[Z/H]¯ = −0.42 ± 0.18) than core slow rotators (Δ[Z/H]¯ = −0.23 ± 0.07). Our results suggest that core and core-less slow rotators have different assembly processes, where the former, as previously discussed, are the relics of massive dissipation-less merging in the presence of central supermassive black holes. Formation processes of core-less slow rotators are consistent with accretion of counter-rotating gas or gas-rich mergers of special orbital configurations, which lower the final net angular momentum of stars, but support star formation. We also highlight core fast rotators as galaxies that share properties of core slow rotators (i.e. cores, ages, σe, and population gradients) and core-less slow rotators (i.e. kinematics, λRe, mass, and larger spread in population gradients). Formation processes similar to those for core-less slow rotators can be invoked to explain the assembly of core fast rotators, with the distinction that these processes form or preserve cores.

scholarly journals Dust properties in the cold and hot gas phases of the ATLAS3D early-type galaxies as revealed by AKARI

2019 ◽  
Vol 622 ◽  
pp. A87 ◽  
Author(s):  
T. Kokusho ◽  
H. Kaneda ◽  
M. Bureau ◽  
T. Suzuki ◽  
K. Murata ◽  
...  
Keyword(s):  
Star Formation ◽  
Virgo Cluster ◽  
Spectral Energy ◽  
X Rays ◽  
Early Type ◽  
Late Type ◽  
X Ray ◽  
Gas Phases ◽  
Hot Gas ◽  
Fast Rotating

Context. The properties of the dust in the cold and hot gas phases of early-type galaxies (ETGs) are key to understanding ETG evolution. Aims. We aim to conduct a systematic study of the dust in a large sample of local ETGs, focusing on relations between the dust and the molecular, atomic, and X-ray gas of the galaxies, as well as their environment. Methods. We estimated the dust temperatures and masses of the 260 ETGs from the ATLAS3D survey, using fits to their spectral energy distributions primarily constructed from AKARI measurements. We also used literature measurements of the cold (CO and H I) and X-ray gas phases. Results. Our ETGs show no correlation between their dust and stellar masses, suggesting inefficient dust production by stars and/or dust destruction in X-ray gas. The global dust-to-gas mass ratios of ETGs are generally lower than those of late-type galaxies, likely due to dust-poor H I envelopes in ETGs. They are also higher in Virgo Cluster ETGs than in group and field ETGs, but the same ratios measured in the central parts of the galaxies only are independent of galaxy environment. Slow-rotating ETGs have systematically lower dust masses than fast-rotating ETGs. The dust masses and X-ray luminosities are correlated in fast-rotating ETGs, whose star formation rates are also correlated with the X-ray luminosities. Conclusions. The correlation between dust and X-rays in fast-rotating ETGs appears to be caused by residual star formation, while slow-rotating ETGs are likely well evolved, and have therefore exhausted their dust. These results appear consistent with the postulated evolution of ETGs, whereby fast-rotating ETGs form by mergers of late-type galaxies and associated bulge growth, while slow-rotating ETGs form by (dry) mergers of fast-rotating ETGs. Central cold dense gas appears to be resilient against ram pressure stripping, suggesting that Virgo Cluster ETGs may not suffer strong related suppression of star formation.

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