Mass Distributions of Galaxies from SAURON and CALIFA Stellar Kinematic Maps

The amount and distribution of dark matter in galaxies defines the formation, evolution and dynamics of these systems. In this thesis we infer the internal mass distributions of 26 E–Sd galaxies using SAURON and CALIFA two-dimensional stellar kinematic maps. We compare two modeling approaches – fitting a solution of the axisymmetric Jeans equations and the commonly applied asymmetric drift correction (ADC). We show that ADC underestimates the enclosed mass by a factor of ∼3-4 once random motion (velocity dispersion) becomes significant com- pared to ordered motion (streaming), that is, when the ratio of ordered-over-random motion is less than about 1.5. Such kinematics indicate that the stellar mass of the galaxy is not confined to the disk plane, as happens in bulges and thick disks of spiral galaxies, as well as in elliptical galaxies. Since this is frequently realized in our sample, as well as in the general galaxy population, a full line-of-sight integration as provided by solutions of the axisymmetric Jeans equation is needed to reliably infer mass distributions in galaxies. We henceforth use the more realistic Jeans models to estimate the dark matter fraction (fDM), by modeling the total (dynamical) mass-to-light ratio and comparing it with the value derived for stars (baryons) from stellar population models. We find several trends of dark matter fraction with global galaxy properties. Ellipticals (E) and late-type spiral (Scd–Sd) galaxies are the most dark matter-dominated objects, while lenticular (S0) and early-type spirals (Sa–Sb) have significantly smaller dark matter fractions. On average, fDM increases both at highest and lowest galaxy (stellar) masses, and is smaller at intermediate masses. Further, it is also anticorrelated with the ratio of ordered-over-random motion, that is dispersion-dominated galaxies show a higher dark matter fraction. Finally, we investigate the maximum circular velocities and qualitative shape of rotation curves as a function of galaxy morphological type along the Hubble sequence. Peaked rotation curves are found in early-type galaxies, while slowly rising rotation curves are typical for late-type spirals. This confirms predictions of recent simulations of galaxy evolution with local photoionization feedback. More generally, our results for dark matter content and dynamics provide empirical constraints on current and future theoretical models of galaxy evolution across a wide range of galaxy morphological types and masses, and thereby will help us to understand the relevant physical processes

The inner mass distribution of late-type spiral galaxies from SAURON stellar kinematic maps

We infer the central mass distributions within 0.4-1.2 disc scale lengths of 18 late-type spiral galaxies using two different dynamical modelling approaches - the Asymmetric Drift Correction (ADC) and axisymmetric Jeans Anisotropic Multi-gaussian expansion (JAM) model. ADC adopts a thin disc assumption, whereas JAM does a full line-of-sight velocity integration. We use stellar kinematics maps obtained with the integral-field spectrograph SAURON to derive the corresponding circular velocity curves from the two models. To find their best-fit values, we apply Markov Chain Monte Carlo (MCMC) method. ADC and JAM modelling approaches are consistent within 5% uncertainty when the ordered motions are significant comparable to the random motions, i.e, $\overline{v_{\phi}}/\sigma_R$ is locally greater than 1.5. Below this value, the ratio $v_\mathrm{c,JAM}/v_\mathrm{c,ADC}$ gradually increases with decreasing $\overline{v_{\phi}}/\sigma_R$, reaching $v_\mathrm{c,JAM}\approx 2 \times v_\mathrm{c,ADC}$. Such conditions indicate that the stellar masses of the galaxies in our sample are not confined to their disk planes and likely have a non-negligible contribution from their bulges and thick disks.Comment: 44 pages, 60 figures, MNRAS accepted. The ADC-MCMC and JAM-MCMC python codes are available at: https://github.com/Kalinova/Dyn_models. The Multi-Gaussian Expansion (MGE) results are also available in the Appendi

The GMRT archive atomic gas survey -- II. Mass modelling and dark matter halo properties across late-type spirals

Studying the kinematics and mass modelling of galaxies from HI 21 cm data provides valuable insights into the properties of both the baryonic components and the dark matter halo in nearby galaxies. Despite many observational studies, mass modelling of galaxies remains challenging due to different limitations. For example, most of the previous studies involving mass modelling are based on rotation curves derived from two-dimensional velocity fields from HI or H$\alpha$ spectroscopic observation which are often affected by beam smearing and projection effect. However, kinematic modelling done by fitting the "Tilted ring model" to three-dimensional data cube is not affected by these issues. In this study, we present and compare 3D kinematic modelling of a pilot sample of eleven galaxies from the GMRT archive atomic gas survey (GARCIA) using two different publicly available pipelines. We model the observed HI rotation curve using 3.6 $\mu$m infrared data and SDSS r-band data for stellar contribution, HI surface density profile for gas, and Navarro-Frenk-White (NFW) profile for dark matter halo; and employ the Markov Chain Monte Carlo (MCMC) optimization method for parameter estimation. Further, to validate our analysis, we revisit important scaling relations, e.g., the M$_{gas}$-M$_{star}$ relation, M$_{star}$-M$_{halo}$ relation, M$_{gas}$-M$_{halo}$ relation and Baryonic Tully-Fisher relation (BTFR). The scaling relations from our analysis are broadly consistent with that reported in the literature. A larger sample of galaxies from GARCIA in the near future will allow studying these scaling relations in greater details.Comment: 16 pages, (9+1) figures. (Accepted for publication in MNRAS

The EDGE-CALIFA Survey: Evidence for Pervasive Extraplanar Diffuse Ionized Gas in Nearby Edge-On Galaxies

We investigate the prevalence, properties, and kinematics of extraplanar diffuse ionized gas (eDIG) in a sample of 25 edge-on galaxies selected from the CALIFA survey. We measure ionized gas scale heights from ${\rm H\alpha}$ and find that 90% have measurable scale heights with a median of $0.8^{+0.7}_{-0.4}$ kpc. From the ${\rm H\alpha}$ kinematics, we find that 60% of galaxies show a decrease in the rotation velocity as a function of height above the midplane. This lag is characteristic of eDIG, and we measure a median lag of 21 km s$^{-1}$ kpc$^{-1}$ which is comparable to lags measured in the literature. We also investigate variations in the lag with radius. $\rm H{\small I}$ lags have been reported to systematically decrease with galactocentric radius. We find both increasing and decreasing ionized gas lags with radius, as well as a large number of galaxies consistent with no radial lag variation, and investigate these results in the context of internal and external origins for the lagging ionized gas. We confirm that the ${\rm [S{\small II}]}$/${\rm H\alpha}$ and ${\rm [N{\small II}]}$/${\rm H\alpha}$ line ratios increase with height above the midplane as is characteristic of eDIG. The ionization of the eDIG is dominated by star-forming complexes (leaky ${\rm H{\small II}}$ regions). We conclude that the lagging ionized gas is turbulent ejected gas likely resulting from star formation activity in the disk as opposed to gas in the stellar thick disk or bulge. This is further evidence for the eDIG being a product of stellar feedback and for the pervasiveness of this WIM-like phase in many local star-forming galaxies.Comment: 36 pages (including 13 appendix pages), 17 figures, resubmitted to ApJ after one round of refereein

Towards a new classification of galaxies: principal component analysis of CALIFA circular velocity curves

We present a galaxy classification system for 238 (E1-Sdm) CALIFA (Calar Alto Legacy Integral Field Area) galaxies based on the shapes and amplitudes of their circular velocity curves (CVCs). We infer the CVCs from the de-projected surface brightness of the galaxies, after scaling by a constant mass-to-light ratio based on stellar dynamics - solving axisymmetric Jeans equations via fitting the second velocity moment $V_{\mathrm{rms}}=\sqrt{V^2+\sigma^2}$ of the stellar kinematics. We use principal component analysis (PCA) applied to the CVC shapes to find characteristic features and use a $k$-means classifier to separate circular curves into classes. This objective classification method identifies four different classes, which we name slow-rising (SR), flat (FL), round-peaked (RP) and sharp-peaked (SP) circular curves. SR are typical for low-mass, late-type (Sb-Sdm), young, faint, metal-poor and disc-dominated galaxies. SP are typical for high-mass, early-type (E1-E7), old, bright, metal-rich and bulge-dominated galaxies. FL and RP appear presented by galaxies with intermediate mass, age, luminosity, metallicity, bulge-to-disk ratio and morphologies (E4-S0a, Sa-Sbc). The discrepancy mass factor, $f_d=1-M_{*}/M_{dyn}$, have the largest value for SR and SP classes ($\sim$ 74 per cent and $\sim$ 71 per cent, respectively) in contrast to the FL and RP classes (with $\sim$ 59 per cent and $\sim$ 61 per cent, respectively). Circular curve classification presents an alternative to typical morphological classification and appears more tightly linked to galaxy evolution.Comment: Accepted for publication in MNRAS (Minor changes), 123 pages, 19 figures, 87 Tables (containing the basic properties of the 238 E1-Sdm galaxies; the five main Principal Component Eigenvectors; the five main Principal Components - PC_i; the Multi-Gaussian Expansion models - MGEs; the circular velocity curve models and their uncertainties

The EDGE-CALIFA survey: Using optical extinction to probe the spatially resolved distribution of gas in nearby galaxies

We present an empirical relation between the cold gas surface density (Σgas) and the optical extinction (AV) in a sample of 103 galaxies from the Extragalactic Database for Galaxy Evolution (EDGE) survey. This survey provides CARMA interferometric CO observations for 126 galaxies included in the Calar Alto Legacy Integral Field Area (CALIFA) survey. The matched, spatially resolved nature of these data sets allows us to derive the Σgas-AV relation on global, radial, and kpc (spaxel) scales. We determine AV from the Balmer decrement (H α/H β). We find that the best fit for this relation is Σgas (M☉ pc−2) ∼ 26 × AV (mag), and that it does not depend on the spatial scale used for the fit. However, the scatter in the fits increases as we probe smaller spatial scales, reflecting the complex relative spatial distributions of stars, gas, and dust. We investigate the Σgas/AV ratio on radial and spaxel scales as a function of EW(H α). We find that at larger values of EW(H α ) (i.e. actively star-forming regions) this ratio tends to converge to twice the value expected for a foreground dust screen geometry (∼30 M☉ pc−2 mag−1). On radial scales, we do not find a significant relation between the Σgas/AV ratio and the ionized gas metallicity. We contrast our estimates of Σgas using AV with compilations in the literature of the gas fraction on global and radial scales as well as with well-known scaling relations such as the radial star formation law and the Σgas-Σ∗ relation. These tests show that optical extinction is a reliable proxy for estimating Σgas in the absence of direct sub/millimeter observations of the cold gas.Fil: Barrera Ballesteros, Jorge K.. Universidad Nacional Autónoma de México; MéxicoFil: Utomo, Dyas. Ohio State University; Estados UnidosFil: Bolatto, Alberto. University of Maryland; Estados UnidosFil: Sánchez, Sebastián F.. Universidad Nacional Autónoma de México; MéxicoFil: Vogel, Stuart N.. University of Maryland; Estados UnidosFil: Wong, Tony. University of Illinois; Estados UnidosFil: Levy, Rebecca C.. University of Maryland; Estados UnidosFil: Colombo, Dario. Max Planck Institut Fur Radioastronomie; AlemaniaFil: Kalinova, Veselina. Max Planck Institut Fur Radioastronomie; AlemaniaFil: Teuben, Peter. University of Maryland; Estados UnidosFil: García Benito, Rubén. Instituto de Astrofísica de Andalucía; EspañaFil: Husemann, Bernd. Max Planck Institut Fur Astronomie; AlemaniaFil: Mast, Damian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Blitz, Leo. University of California at Berkeley; Estados Unido

The EDGE-CALIFA Survey: Interferometric Observations of 126 Galaxies with CARMA

We present interferometric CO observations, made with the Combined Array for Millimeter-wave Astronomy (CARMA) interferometer, of galaxies from the Extragalactic Database for Galaxy Evolution survey (EDGE). These galaxies are selected from the Calar Alto Legacy Integral Field Area (CALIFA) sample, mapped with optical integral field spectroscopy. EDGE provides good-quality CO data (3σ sensitivity before inclination correction, resolution ∼1.4 kpc) for 126 galaxies, constituting the largest interferometric CO survey of galaxies in the nearby universe. We describe the survey and data characteristics and products, then present initial science results. We find that the exponential scale lengths of the molecular, stellar, and star-forming disks are approximately equal, and galaxies that are more compact in molecular gas than in stars tend to show signs of interaction. We characterize the molecular-to-stellar ratio as a function of Hubble type and stellar mass and present preliminary results on the resolved relations between the molecular gas, stars, and star-formation rate. We then discuss the dependence of the resolved molecular depletion time on stellar surface density, nebular extinction, and gas metallicity. EDGE provides a key data set to address outstanding topics regarding gas and its role in star formation and galaxy evolution, which will be publicly available on completion of the quality assessment.Fil: Bolatto, Alberto. University of Maryland; Estados UnidosFil: Wong, Tony. University of Illinois at Urbana; Estados UnidosFil: Utomo, Dyas. University of California at Berkeley; Estados UnidosFil: Blitz, Leo. University of California at Berkeley; Estados UnidosFil: Vogel, Stuart N.. University of Maryland; Estados UnidosFil: Sánchez, Sebastián F.. Universidad Nacional Autónoma de México; MéxicoFil: Barrera-Ballesteros, Jorge. University Johns Hopkins; Estados UnidosFil: Cao, Yixian. University of Illinois; Estados UnidosFil: Colombo, Dario. Max Planck Institut Fur Radioastronomie; AlemaniaFil: Dannerbauer, Helmut. Universidad de La Laguna; EspañaFil: García-Benito, Rubén. Instituto de Astrofísica de Andalucía; EspañaFil: Herrera-Camus, Rodrigo. Max Planck Institute für Extraterrestrische Physik; AlemaniaFil: Husemann, Bernd. Max-Planck-Institut für Astronomie; AlemaniaFil: Kalinova, Veselina. Max Planck Institut für Radioastronomie; AlemaniaFil: Leroy, Adam K.. Ohio State University; Estados UnidosFil: Leung, Gigi. Max-Planck-Institut für Astronomie; AlemaniaFil: Levy, Rebecca C.. University of Maryland; Estados UnidosFil: Mast, Damian. Observatorio Astronomico de la Universidad Nacional de Cordoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Ostriker, Eve. University of Princeton; Estados UnidosFil: Rosolowsky, Erik. University of Alberta; CanadáFil: Sandstrom, Karin M.. University of California at San Diego; Estados UnidosFil: Teuben, Peter. University of Maryland; Estados UnidosFil: Van De Ven, Glenn. Max-Planck-Institut für Astronomie; AlemaniaFil: Walter, Fabian. Max-Planck-Institut für Astronomie; Alemani

The EDGE-CALIFA survey: Molecular Gas and Star Formation Activity Across the Green Valley

We present a $^{12}$CO($J$=2-1) survey of 60 local galaxies using data from the Atacama Large Millimeter/submillimeter Compact Array as part of the Extragalactic Database for Galaxy Evolution: the ACA EDGE survey. These galaxies all have integral field spectroscopy from the CALIFA survey. Compared to other local galaxy surveys, ACA EDGE is designed to mitigate selection effects based on CO brightness and morphological type. Of the 60 galaxies in ACA EDGE, 36 are on the star-formation main sequence, 13 are on the red sequence, and 11 lie in the ``green valley" transition between these sequences. We test how star formation quenching processes affect the star formation rate (SFR) per unit molecular gas mass, SFE$_{\rm mol}=$SFR/$M_{\rm mol}$, and related quantities in galaxies with stellar masses $10\leq$log[$M_\star/$M$_\odot$]$\leq11.5$ covering the full range of morphological types. We observe a systematic decrease of the molecular-to-stellar mass fraction ($R^{\rm mol}_{\star}$) with decreasing level of star formation activity, with green valley galaxies having also lower SFE$_{\rm mol}$ than galaxies on the main sequence. On average, we find that the spatially resolved SFE$_{\rm mol}$ within the bulge region of green valley galaxies is lower than in the bulges of main sequence galaxies if we adopt a constant CO-to-H$_2$ conversion factor, $\alpha_{\rm CO}$. While efficiencies in main sequence galaxies remain almost constant with galactocentric radius, in green valley galaxies we note a systematic increase of SFE$_{\rm mol}$, $R^{\rm mol}_{\star}$, and specific star formation rate, sSFR, with increasing radius. Our results suggest that although gas depletion (or removal) seems to be the most important driver of the star-formation quenching in galaxies transiting through the green valley, a reduction in star formation efficiency is also required during this stage

The EDGE-CALIFA survey: Central molecular gas depletion in AGN host galaxies - A smoking gun for quenching?

Feedback from an active galactic nucleus (AGN) is often implicated as a mechanism that leads to the quenching of galactic star formation. However, AGN-driven quenching is challenging to reconcile with observations that AGN hosts tend to harbour equal (or even excess) amounts of gas compared with inactive galaxies of similar stellar mass. In this paper, we investigate whether AGN feedback happens on sub-galactic (kpc) scales, an effect that might be difficult to detect with global gas measurements. Using kpc-scale measurements of molecular gas (ΣH2) and stellar mass (Σ∗) surface densities, taken from the Extragalactic Data base for Galaxy Evolution-Calar Alto Legacy Integral Field Area survey, we show that the gas fractions of central AGN regions are typically a factor of ∼2 lower than those in star-forming regions. Based on four galaxies with the best spaxel statistics, the difference between AGN and star-forming gas fractions is seen even within a given galaxy, indicating that AGN feedback is able to deplete the molecular gas reservoir in the central few kpc. © 2021 The Author(s).The authors acknowledge an NSERC Discovery Grant (SLE), NSF AST-1616199 (TW), support by the Deutsche Forschungsgemeinschaft project number SFB956A (DC), NSF AST-1615960 (AB, SNV), PID2019-109067GB-I00, P18-FRJ-2595, SEV-2017-0709 (RGB), IA-100420, IN100519, CF19-39578, CB-285080, and FC-2016-01-1916 (SFS and JBB),and Fondecyt grant number 1190684 (MR). Support for CARMA construction was derived from the Gordon and Betty Moore Foundation, the Eileen and Kenneth Norris Foundation, the Caltech Associates, the states of California, Illinois, and Maryland, and the NSF. Funding for CARMA development and operations was supported by NSF and the CARMA partner universities. We acknowledge the usage of the HyperLeda data base (http://leda.univ-lyon1.fr).Peer reviewe