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Globular Cluster Populations: First Results from S4G Early-type Galaxies

Globular Cluster Populations: First Results from S4G Early-type Galaxies

the sources have absolute magnitudes consistent with those expected for globular clusters; (4) the radial distribution of sources, where that is well-measured, lie in the range of r − 2 to r −4 , which is consistent with previous measurements (Ashman & Zepf 1998; Brodie & Strader 2006); (5) the number of excess sources, ranging from a few up to a thousand, are in the range expected based on previous cluster population studies (Harris 1991; Brodie & Strader 2006); and (6) in the few cases where we can compare our measurements to higher-fidelity measurements in the literature, we reproduce prior results. From now on, we will refer to these excess sources as clusters, although it must be understood that these populations could be partially contaminated by other sources that also cluster about the parent galaxy. In general, one possible such source would be star-forming knots (Thilker et al. 2005; Gil de Paz et al. 2005; Zaritsky & Christlein 2007; Herbert-Fort et al. 2012) and intermediate-age versions of such structures, although for our early-type galaxies those should not be a major source of contamination. Individual stars are generally insufficiently luminous to match our magnitude criteria (−11 < M 3.6 <
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The SAMI galaxy survey : kinematics of dusty early type galaxies

The SAMI galaxy survey : kinematics of dusty early type galaxies

Recently, large samples of visually classified early-type galaxies (ETGs) containing dust have been identified using space-based infrared observations with the Herschel Space Telescope. The presence of large quantities of dust in massive ETGs is peculiar as X-ray haloes of these galaxies are expected to destroy dust in ∼10 7 yr (or less). This has sparked a debate regarding the origin of the dust: Is it internally produced by asymptotic giant branch stars, or is it accreted externally through mergers? We examine the 2D stellar and ionized gas kinematics of dusty ETGs using integral field spectroscopy observations from the SAMI Galaxy Survey, and integrated star formation rates, stellar masses and dust masses from the GAMA survey. Only 8 per cent (4/49) of visually classified ETGs are kinematically consistent with being dispersion-supported systems. These ‘dispersion-dominated galaxies’ exhibit discrepancies between stellar and ionized gas kinematics, either offsets in the kinematic position angle or large differences in the rotational velocity, and are outliers in star formation rate at a fixed dust mass compared to normal star-forming galaxies. These properties are suggestive of recent merger activity. The remaining ∼90 per cent of dusty ETGs have low velocity dispersions and/or large circular velocities, typical of ‘rotation-dominated galaxies’. These results, along with the general evidence of published works on X-ray emission in ETGs, suggest that they are unlikely to host hot, X-ray gas consistent with their low M ∗ when compared to dispersion- dominated galaxies. This means that dust will be long-lived and thus these galaxies do not require external scenarios for the origin of their dust content.
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The ATLAS3D project   XXVII  Cold gas and the colours and ages of early type galaxies

The ATLAS3D project XXVII Cold gas and the colours and ages of early type galaxies

with aligned gas. Specifically, Kolmogorov-Smirnov and Mann- Whitney U tests on the galaxy colours, equivalent SSP ages, metal- licities, α-element abundances, stellar velocity dispersions, specific stellar angular momenta, and photometric disc-to-total light ratios give probabilities 0.13 to 0.99, none of which are small enough to infer a difference in the two populations. Ultimately the ques- tion may be decided through detailed exploration of the individ- ual galaxies’ star formation histories (McDermid et al. 2013), with deep optical imaging and measurements of the current star forma- tion rates and gas depletion time-scales. At present we conclude that the cold gas in early-type galaxies includes some gas which may have been retained through the quenching transition to the red sequence, as well as some gas acquired in a major merger or accreted from an external source such as a satellite galaxy or the
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SDSS IV MaNGA: probing the kinematic morphology–density relation of early type galaxies with MaNGA

SDSS IV MaNGA: probing the kinematic morphology–density relation of early type galaxies with MaNGA

The angular momentum content of galaxies can serve as a probe of their assembly histories. Although early-type galaxies are dynamically hot systems, many of them show some rotation ( e.g., Davies et al. 1983; Franx & Illingworth 1990 ) . The evolution in angular momentum of galaxies is in fl uenced in complex ways by mergers ( both major or minor ) , gas accretion, and internal processes such as star formation that either turn gas into stars or expel gas ( e.g., Penoyre et al. 2017 ) . Mergers, for instance, might increase or decrease the angular momentum depending on the con fi guration ( e.g., Naab et al. 2014 ) . Tracking the evolution in angular momentum content with galaxy properties is a tracer of the factors that dominate galaxy evolution.
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H ATLAS/GAMA and HeViCS – dusty early type galaxies in different environments

H ATLAS/GAMA and HeViCS – dusty early type galaxies in different environments

Dust is a fundamental component of the interstellar medium (ISM) of galaxies for the thermodynamics and chemistry of the gas, for the dynamics of the accretion in dense star-forming clouds, and for the attenuation of UV/blue radiation and its re-emission in the far-infrared (FIR; Draine 2003). The relative amount of dust varies strongly with galaxy type, increasing by about three orders of mag- nitude on average along the Hubble sequence (e.g. Cortese et al. 2012a). The connection between dust and chemical evolution also varies with galaxy type. In late-type galaxies (LTG) dust is strongly linked with star formation (SF), both because it serves as a catalyst for the formation of molecular gas necessary for SF and because, being heated mostly by young stars, its emission traces the regions of SF. The same paradigm does not necessarily apply to early-type galaxies (ETG; comprising of ellipticals and lenticulars), where dust can be heated by the radiation field produced by evolved stars and can be more diffuse, therefore not serving as an SF catalyst. In addition, ETG, particularly those in clusters, can have much larger amounts of hot gas than LTG, not favouring the presence of dust.
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The ATLAS3D Project   XXVIII  Dynamically driven star formation suppression in early type galaxies

The ATLAS3D Project XXVIII Dynamically driven star formation suppression in early type galaxies

We also plot in Figure 8, panel a) a simple mixing model (shown as a dashed line). This toy model assumes that two star for- mation regimes exist within early-type galaxies, one with very low SFE (which is valid in the rising part of the rotation curve), and one with a normal SFE, similar to that found in local spirals (which is valid in the flat part of the galaxy rotation curve). We assume de- pletion times of 0.8 Gyr for the normal regime, and a Hubble time for the low SFE regime respectively. We then assume all the gas is distributed in an exponential disc (which is only true for ≈ 50% of these sources; Paper XIV), and that the maximum gas extent we can measure corresponds to 3 scale lengths. We then vary the scale length of this disc with respect to the turnover of rotation curve, and calculate a model ”integrated” depletion time by weighting the two assumed depletion times by the fraction of gas in each regime. This leads to the curve shown in 8. This toy model is likely to be a vast over-simplification, and the exact values of all the assumed parame- ters were simply selected to provide a by-eye fit to the data. Despite this, the functional form produced by such a toy model reasonably matches the behaviour seen in the data, suggesting that the suppres- sion of star formation we observe may be driven by the fraction of gas which is inside the turnover radius.
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SDSS IV MaNGA: uncovering the angular momentum content of central and satellite early type galaxies

SDSS IV MaNGA: uncovering the angular momentum content of central and satellite early type galaxies

galaxies. We compare our results with their predictions here. Several studies ( e.g., Khochfar & Burkert 2005; Naab et al. 2006; Kang et al. 2007 ) have argued that the dichotomy of early-type galaxies can be explained in a scenario whereby boxy, slowly rotating ellipticals have their origin in a merger that is both major ( i.e., mass ratio of progenitors close to unity ) and dry ( i.e., progenitors have small gas mass fractions ) . In particular, Kang et al. ( 2007 ) conclude that the observed stellar mass dependence of the boxy fraction requires that slow rotators result from mergers with a progenitor mass ratio < 2 and with a combined cold gas mass fraction < 0.1. Lagos et al. ( 2017 ) also fi nd that major merging is a primary driver of angular momentum evolution. Interestingly, Choi & Yi ( 2017 ) fi nd that the cluster galaxies in their simulations with no major merging are the ones with the most rapid decrease in l R , but
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An ALMA view of star formation efficiency suppression in early type galaxies after gas rich minor mergers

An ALMA view of star formation efficiency suppression in early type galaxies after gas rich minor mergers

Gas-rich minor mergers contribute significantly to the gas reservoir of early-type galaxies (ETGs) at low redshift, yet the star formation efficiency (SFE; the star formation rate divided by the molecular gas mass) appears to be strongly suppressed following some of these events, in contrast to the more well-known merger-driven starbursts. We present observations with the Atacama Large Millimeter/submillimeter Array (ALMA) of six ETGs, which have each recently undergone a gas-rich minor merger, as evidenced by their disturbed stellar morpholo- gies. These galaxies were selected because they exhibit extremely low SFEs. We use the resolving power of ALMA to study the morphology and kinematics of the molecular gas. The majority of our galaxies exhibit spatial and kinematical irregularities, such as detached gas clouds, warps, and other asymmetries. These asymmetries support the interpretation that the suppression of the SFE is caused by dynamical effects stabilizing the gas against gravitational collapse. Through kinematic modelling we derive high velocity dispersions and Toomre Q stability parameters for the gas, but caution that such measurements in edge-on galaxies suf- fer from degeneracies. We estimate merger ages to be about 100 Myr based on the observed disturbances in the gas distribution. Furthermore, we determine that these galaxies lie, on aver- age, two orders of magnitude below the Kennicutt–Schmidt relation for star-forming galaxies as well as below the relation for relaxed ETGs. We discuss potential dynamical processes responsible for this strong suppression of star formation surface density at fixed molecular gas surface density.
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Monsters in the deep: using simulations to understand the excess baryonic mass in the centres of high-mass, early-type galaxies

Monsters in the deep: using simulations to understand the excess baryonic mass in the centres of high-mass, early-type galaxies

Recently, some studies have had success at measuring the IMF in external galaxies, particularly in the central regions of high-mass early-type galaxies (ETGs). One method of doing so is to measure the stellar M / L ratio dynamically, by modelling the motions of the stars under the assumption that the system is dynamically relaxed, and making some assumption of the contribution to the gravitational potential of dark matter and a supermassive BH. Such studies have found that the stellar mass-to-light ratio, measured dynamically, is larger than would be expected given a standard MW- like IMF (e.g. Thomas et al. 2011b; Dutton et al. 2012; Tortora et al. 2013; Cappellari et al. 2013b; Li et al. 2017). This excess mass-to-light ratio (hereafter referred to as the MLE) appears to increase with the stellar velocity dispersion of the galaxy, which is closely related to its mass. From these observations alone, it is difficult to determine how the IMF is actually varying, as the extra “invisible” stellar mass may be due to an excess of very faint low-mass stars (a “bottom-heavy” IMF), or to high-mass stars, which have died long ago and left behind BHs and neutron stars (a “top-heavy” IMF). A method of solving this degeneracy is by constraining the IMF through spectroscopy. Stellar spectra contain absorption lines that are sensitive to the surface gravity (and hence the mass) of a star, where, at fixed metallicity and age, some lines are stronger in dwarfs than in giant stars, and vice versa (e.g. Conroy & van Dokkum 2012a; La Barbera et al. 2013). It is thus possible to constrain the ratio of dwarf-to- giant stars in a given stellar population by fitting stellar population synthesis models to the spectra with the IMF as a free parameter. It is, however, unclear how the shape of the IMF should vary, since the dwarf-to-giant ratio can be increased by steepening the IMF slope at all masses (e.g. Spiniello et al. 2014), only at low masses (e.g. Conroy & van Dokkum 2012b; Conroy et al. 2017), or only at high masses (e.g. La Barbera et al. 2013). However, the choice of IMF parametrization can be critical for models of galaxy formation, since the high-mass end of the IMF governs stellar feedback and metal enrichment (e.g. Martín-Navarro 2016). Another issue is that the strengths of these IMF-sensitive absorption features often also depend on metallicity, so determination of the IMF may depend on one’s ability to separate these potentially degenerate variables (e.g. Vaughan et al. 2018a). Nevertheless, the majority of studies which constrain the IMF spectroscopically conclude that the dwarf-to-giant ratio, and thus the MLE, increases with stellar velocity dispersion in the centres of ETGs, in agreement with IMF constraints based on kinematics (Cenarro et al. 2003; Van Dokkum & Conroy 2010; Conroy & van Dokkum 2012b; Spiniello et al. 2012; Ferreras et al. 2013; La Barbera et al. 2013, 2015; Spiniello et al. 2014; Rosani et al. 2018).
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An ALMA view of star formation efficiency suppression in early-type galaxies after gas-rich minor mergers

An ALMA view of star formation efficiency suppression in early-type galaxies after gas-rich minor mergers

Gas-rich minor mergers contribute significantly to the gas reservoir of early-type galaxies (ETGs) at low redshift, yet the star formation efficiency (SFE; the star for- mation rate divided by the molecular gas mass) appears to be strongly suppressed following some of these events, in contrast to the more well-known merger-driven star- bursts. We present observations with the Atacama Large Millimeter/submillimeter Array (ALMA) of six ETGs, which have each recently undergone a gas-rich minor merger, as evidenced by their disturbed stellar morphologies. These galaxies were se- lected because they exhibit extremely low SFEs. We use the resolving power of ALMA to study the morphology and kinematics of the molecular gas. The majority of our galaxies exhibit spatial and kinematical irregularities, such as detached gas clouds, warps, and other asymmetries. These asymmetries support the interpretation that the suppression of the SFE is caused by dynamical effects stabilizing the gas against grav- itational collapse. Through kinematic modelling we derive high velocity dispersions and Toomre Q stability parameters for the gas, but caution that such measurements in edge-on galaxies suffer from degeneracies. We estimate merger ages to be about 100 Myr based on the observed disturbances in the gas distribution. Furthermore, we determine that these galaxies lie, on average, two orders of magnitude below the Kennicutt-Schmidt relation for star-forming galaxies as well as below the relation for relaxed ETGs. We discuss potential dynamical processes responsible for this strong suppression of star formation surface density at fixed molecular gas surface density.
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Bondi accretion in early-type galaxies

Bondi accretion in early-type galaxies

sider that corresponding to the Hernquist (1990) density profile that describes well the mass distribution of early-type galaxies; however, we stress that several results below remain true also for other galaxy models, such as the so-called γ -models (Dehnen 1993; Tremaine et al. 1994). The Hernquist model with a central MBH has been recently adopted for a numerical investigation of the bulge- driven, Bondi fuelling of seed black holes (Park et al. 2016); our analysis below nicely reinforces their conclusions, and provides an- alytical explanations for some of the scalings they find (see also Appendix C). The gravitational potential of the Hernquist model is φ g = −
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Relation between dust and radio luminosity in optically selected early type galaxies

Relation between dust and radio luminosity in optically selected early type galaxies

would mark them as starburst, although they still might have nuclear AGN which are the subject under discussion. Using the large scale IR emission to determine the nature of the nu- clear radio emission does not seem to be a very good discrim- inator between SBs and AGNs. However, most of our objects have measured nuclear Hα fluxes or upper limits (Tran, private communication), and standard calculations (Osterbrock 1989) indicate that the free-free fluxes from these regions would be below 3 µJy, which is about two to three orders of magnitude smaller than our observed fluxes. Other evidence that we are dealing with non-thermal radiation comes from the flatness of the spectra in our sample. Eleven of the galaxies were detected before in the NVSS (Condon et al. 1998) and comparing the fluxes at our frequency (8.45 GHz) and the frequency of the NVSS (1.4 GHz) it is clear that most of the detected galaxies have flat spectra (Table 1).
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Imprints of recoiling massive black holes on the hot gas of early type galaxies

Imprints of recoiling massive black holes on the hot gas of early type galaxies

It is important to note that the X-ray features recognized in this work are not due to the direct emission from the BH but only due to the perturbed large-scale hot gas of the underlying galaxy. In addition to this, the BH itself can produce its own optical and X-ray emission if it is able to retain a punctured accretion disc at the moment of its ejection from the centre, as suggested by Loeb (2007) (and studied in a statistical context by Volonteri & Madau 2008). The kicked BH in this case can turn on as a displaced quasi-stellar object (QSO)/active galactic nuclei, and a key manifestation of a large recoil should be imprinted in the line systems shifted in veloc- ity from the host galaxies (Bonning, Shields & Salviander 2007). This off-nuclear QSO emission can coexist with the large-scale emission features studied in this paper. The contemporary observa- tion of a set of offset lines and a Mach cone can potentially provide information on the tangential and radial velocities resulting from the kick. Off-centred flares occurring from tidal disruption of bound stars or from marginally bound gas that infall on the disc can also be present during the lifetime of the recoiling BH (Merritt, Schnittman & Komossa 2008; O’Leary & Loeb 2008; Shields & Bonning 2008). The electromagnetic signature of a recoiling BH, detailed in this paper, is different from the one expected in the immediate vicinity of a coalescence event. Electromagnetic afterglows of LISA coa- lescence events (Milosavljevi´c & Phinney 2005; Dotti et al. 2006; Kocsis & Loeb 2008; Lippai, Frei & Haiman 2008) have peculiar off–on time-dependent features varying on much shorter times and spatial scales.
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The dark and luminous structure of early type galaxies : observational dynamics and stellar populations

The dark and luminous structure of early type galaxies : observational dynamics and stellar populations

Emsellem et al. (2007) and Emsellem et al. (2011) both used ETG kinematics from the SAURON integral-field-unit (IFU) instrument (Bacon et al., 2001), with data from the SAURON (de Zeeuw et al., 2002) and ATLAS 3D (Cappellari et al., 2011a) surveys respectively. The ATLAS 3D survey in particular was notable for containing data of 260 nearby ETGs, represent- ing a significant step up from previous studies of its kind. Analysis of the SAURON and ATLAS 3D stellar kinematics led to a much-improved understanding of ETG kinematics with almost all lenticulars as well as most ellipticals being classified as FRs (Emsellem et al., 2007, 2011); a minority of ETGs, which includes the most massive objects, show little ordered motion in their kinematics and are instead classified as SRs. Stellar kinematics have also shown a range of kinematic substructures within individual ETGs, including kinematics twists and kinematically- decoupled cores (Krajnovi´c et al., 2011). Fast-rotating ATLAS 3D ETGs were also shown with these data to have a wide range of bulge fractions, similar to spiral galaxies (Cappellari et al., 2011b); this led to a proposed revision to the Hubble diagram, making use of both mopholog- ical and kinematic ETG properties as shown in Figure 1.2.
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The Atlas3D Project   XXX  Star formation histories and stellar population scaling relations of early type galaxies

The Atlas3D Project XXX Star formation histories and stellar population scaling relations of early type galaxies

We thank the referee, Daniel Thomas, for a constructive report, which helped improve this paper. RMcD would like to thank In- ger Jørgensen for a careful reading of early drafts of this paper, and Ricardo Schiavon for numerous instructive discussions. RMcD and RLD gratefully acknowledge the hospitality of the ESO visi- tor programme during the preparation of this work. MC acknowl- edges support from a Royal Society University Research Fellow- ship. This work was supported by the rolling grants ‘Astrophysics at Oxford’ PP/E001114/1 and ST/H002456/1 and visitor grants PPA/V/S/2002/00553, PP/E001564/1, and ST/H504862/1 from the UK Research Councils. RLD acknowledges travel and computer grants from Christ Church, Oxford and support from the Royal So- ciety in the form of a Wolfson Merit Award 502011.K502/jd. TN acknowledges support from the DFG Cluster of Excellence Ori- gin and Structure of the Universe. MS acknowledges support from an STFC Advanced Fellowship ST/F009186/1. TAD acknowledges the support provided by an ESO fellowship. The research lead- ing to these results has received funding from the European Com- munity’s Seventh Framework Programme (/FP7/2007-2013/) under grant agreement No. 229517. The authors acknowledge financial support from ESO. SK acknowledges support from the Royal So- ciety Joint Projects Grant JP0869822. NS acknowledges support of Australian Research Council grant DP110103509.
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Signatures of stellar accretion in MaNGA early type galaxies

Signatures of stellar accretion in MaNGA early type galaxies

The MaNGA survey (Bundy et al. 2015; Yan et al. 2016a) is part of the fourth generation of SDSS (York et al. 2000; Gunn et al. 2006; Blanton et al. 2017), and is on track to provide spatially resolved spectra for ten thousand nearby galaxies (z < 0.15) by the end of 2020. By means of integral field unit spectroscopy (IFS; Smee et al. 2013; Drory et al. 2015; Law et al. 2015), every galaxy is observed with 19-to-127 fiber bundles with diameters varying between 12. 00 5 and 32. 00 5. The resulting radial coverage reaches between 1.5R e and 2.5R e for

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The Atlas3D project   XXXI  Nuclear radio emission in nearby early type galaxies

The Atlas3D project XXXI Nuclear radio emission in nearby early type galaxies

To help further constrain the most likely origin of the nuclear radio sources (AGN vs. SF), we also incorporated optical and X-ray AGN diagnostics in our study. We found that ETGs with central ionized gas emission are significantly more likely to harbor nuclear radio sources compared to those lacking strong nebular emission lines. LINERs com- prise the most prevalent optical emission line class among our sample galaxies. The LINERs with EW[OIII] in excess of 0.8 ˚ A, which are likely to be associated with a genuine LLAGN as opposed to pAGB stars or shocks, show a partic- ularly strong association with the presence of compact radio emission compared to other classes at the 3σ level. This supports the interpretation that the majority of the nuclear radio sources detected in our study are indeed associated with LLAGNs. This is further supported by available X-ray data in the literature. The radio-X-ray ratios for the subset of the ETGs in our sample with both nuclear radio and X- ray measurements available are consistent with radio-loud emission (as defined by Terashima & Wilson 2003), similar to typical nearby LLAGNs (Ho 2008). Since radio loudness is known to scale inversely with Eddington ratio, this indi- cates that the SMBH accretion in our sample of local ETGs is dominated by radiatively inefficient mechanisms.
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The Atlas3D project   XXIV  The intrinsic shape distribution of early type galaxies

The Atlas3D project XXIV The intrinsic shape distribution of early type galaxies

Shape is a very basic property of a galaxy, yet it contains strong constraints for its formation history, with different merger, accretion and assembly scenarios resulting in differ- ent shapes. Still, intrinsic shapes of individual galaxies are not readily obtained: detailed photometry and kinematical information is needed to construct a dynamical model of a galaxy, and constrain its shape (e.g. Statler 1994; Statler, Lambright & Bak 2001; van den Bosch & van de Ven 2009). Therefore, many studies to obtain intrinsic shapes of galax- ies have focused on large samples, using statistical methods to obtain the underlying intrinsic shape distribution of a particular galaxy population (e.g., Hubble 1926; Sandage, Freeman & Stokes 1970; Lambas, Maddox & Loveday 1992; Tremblay & Merrit 1996; Ryden 2004; Vincent & Ryden 2005; Ryden 2006; Kimm & Yi 2007; Padilla & Strauss 2008; M´endez-Abreu et al. 2010; Yuma, Ohta & Yabe 2012). These studies rely on measurements of the observed elliptic- ities ǫ = 1 − b/a, with b/a the observed axis ratio of the galaxy image, and, in principle, do not require kinematic information (although as we mention later inclusion of kine- matic misalignment provides additional constraints on the shape distribution, e.g. Binney 1985; Franx, Illingworth & de Zeeuw 1991). Especially the Sloan Digital Sky Survey (SDSS) has been a major provider for imaging used in shape studies: recent results based on this survey include the non- circularity of discs in spiral galaxies (Ryden 2004; Padilla & Strauss 2008) and the presence of triaxial and prolate galax- ies in the early-type galaxy population (Vincent & Ryden 2005; Kimm & Yi 2007).
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Misgeld, Ingo
  

(2011):


	Early-type stellar systems in nearby galaxy clusters: from dwarf galaxies to star clusters.


Dissertation, LMU München: Fakultät für Physik

Misgeld, Ingo (2011): Early-type stellar systems in nearby galaxy clusters: from dwarf galaxies to star clusters. Dissertation, LMU München: Fakultät für Physik

and Fig. 5.5). For example, the similar size–mass relation of giant elliptical galaxies, cEs, UCDs, nuclei of dE,Ns and NCs, which sharply defines a maximum stellar mass for a given half-light radius (Eq. (5.8)), translating into a maximum mass surface density, as given by Eq. (5.11), creating a ’zone of avoidance’ beyond these limits. Not only local early-type galaxies do not appear beyond these limits, but also most of the high-redshift galaxies (1 . z . 2) presented here coincide with their local counterparts in the size/surface density–mass plane (see Fig. 5.6). Given the uncertain estimates of stellar masses and effective radii of some of the high-z galaxies (e.g. van Dokkum et al. 2008), they might already at this time be consistent with the z ∼ 0 objects, or they might evolve onto the relations observed for the local galaxies via subsequent merging events (Sect. 5.2.4). However, present data on the structural parameters and stellar masses of high-z ETGs are still rather limited. High quality data for a larger number of ETGs are required to be able to reach a definite conclusion on whether or not these objects are structurally different from their local counterparts.
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