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Hot dust in the proximity of AGNs strongly emits in the Near Infrared producing a red excess that, in type 2 sources, can be modeled to measure its temperature. In the era of high spatial-resolution multi-wavelength data, mapping the hot dust around Supermassive Black Holes is important for the efforts to achieve a complete picture of the dust role and distribution around these compact objects. In this work we propose a methodology to detect the hot dust emission in the proximity of Type 2 AGNs and measure its temperature using K-band spectra ($\lambda_c$ = 2.2\,$\mu$m). To achieve this, we have developed NIRDust, a Python package for modeling K-band spectra, estimate the dust temperature and characterize the involved uncertainties. We tested synthetic and real spectra in order to check the performance and suitability of the physical model over different types of data. Our tests on synthetic spectra demonstrated that the obtained results are influenced by the signal-to-noise ratio (S/N) of the input spectra. However, we accurately characterized the uncertainties, which remained below $\sim$150 K for an average S/N per pixel exceeding 20. Applying NIRDust to NGC 5128 (Centaurus A), observed with the Gemini South Telescope, we estimated a dust temperature of 662 and 667 K from Flamingos-2 spectra and 697 and 607 K from GNIRS spectra using two different approaches., Comment: 12 pages, 7 figures

In this paper we analyse a sample of 46 barred galaxies of MaNGA. Our goal is to investigate the stellar kinematics of these galaxies and obtain their rotation curves. Additionally, we aim to derive the total stellar and dynamical masses, as well as the maximum rotation velocity, in order to examine their distributions and scaling relations. Using the Pipe3D dataproducts publicly available we obtained the rotation curves, which were fitted considering two components of an axisymmetric Miyamoto-Nagai gravitational potential. We found a wide range of the maximum rotation velocities (117 - 340 km s -1 ), with a mean value of 200 km s -1 . In addition we found that the total stellar and dynamical masses are in the range of log(M star /M sun ) = 10.1 - 11.5, with a mean value of log(M star /M sun ) = 10.8, and log(M dyn /M sun ) = 10.4 - 12.0, with a mean value of log(M dyn /M sun ) = 11.1, respectively. We found a strong correlation between dynamical mass and maximum velocity, between maximum velocity and magnitude, and between stellar mass and maximum velocity. According to these results, barred galaxies exhibit similar behaviour to that of normal spiral galaxies with respect to these relations, as well as in terms of the distribution of their dynamical mass and maximum rotation velocity. Ho we ver, we found that the distribution of stellar masses of barred galaxies is statistically different from other samples including non-barred galaxies. Finally, analysing the galaxies that show nuclear activity, we find no difference with the rotation curves of normal galaxies.

NGC 4945 harbors one of the nearest active galactic nuclei (AGN), which allows reaching high spatial resolution with the current observational facilities. The Seyfert 2 nucleus is deeply obscured by an edge-on disk with $A_V\sim14$, requiring infrared observations to study circumnuclear structures and the interstellar medium. In this work, we present an imaging and longslit spectroscopic study of the nuclear region with a spatial resolution of 6.5 pc, based on Flamingos-2 (F2) and T-ReCS data taken at the Gemini South observatory. We report sub-arcsecond photometric measurements of the nucleus in $J$, $H$ and $K_{\rm s}$ filters, and at larger apertures. We do not detect nuclear variability. The nuclear spectra confirm that even in $K$-band the AGN emission-line features are completely obscured by dust. We detect a circumnuclear disk in $K$-band as well as in the mid-infrared (MIR) $N$- and $Q_{\rm a}$-bands, with a radial scale length of $\sim$120 pc. The disk shows knots mostly in a ring-like arrangement that has been previously detected with HST Pa $\alpha$ observations, indicating that these are deeply embedded, massive young star clusters. We present here the spectrum of one of the brightest and unresolved object (R$<5$pc), which we identify as a super star cluster candidate with M$_{K_{\rm s}} -16.6\pm0.4$. For the circumnuclear region, a detailed rotation curve allows to measure a nuclear mass of $M=(4.4 \pm 3)\times 10^{6} M_\odot$ within a radius of $\sim6.5$ pc. We also report the detection of hot dust ($\sim 1000$ K) out to a nuclear distance of 80 pc measured along the semi-major axis., Comment: 20 pages

NGC 4945 harbors one of the nearest active galactic nuclei (AGN), which allows reaching high spatial resolution with the current observational facilities. The Seyfert 2 nucleus is deeply obscured by an edge-on disk with $A_V\sim14$, requiring infrared observations to study circumnuclear structures and the interstellar medium. In this work, we present an imaging and longslit spectroscopic study of the nuclear region with a spatial resolution of 6.5 pc, based on Flamingos-2 (F2) and T-ReCS data taken at the Gemini South observatory. We report sub-arcsecond photometric measurements of the nucleus in $J$, $H$ and $K_{\rm s}$ filters, and at larger apertures. We do not detect nuclear variability. The nuclear spectra confirm that even in $K$-band the AGN emission-line features are completely obscured by dust. We detect a circumnuclear disk in $K$-band as well as in the mid-infrared (MIR) $N$- and $Q_{\rm a}$-bands, with a radial scale length of $\sim$120 pc. The disk shows knots mostly in a ring-like arrangement that has been previously detected with HST Pa $\alpha$ observations, indicating that these are deeply embedded, massive young star clusters. We present here the spectrum of one of the brightest and unresolved object (R$<5$pc), which we identify as a super star cluster candidate with M$_{K_{\rm s}} -16.6\pm0.4$. For the circumnuclear region, a detailed rotation curve allows to measure a nuclear mass of $M=(4.4 \pm 3)\times 10^{6} M_\odot$ within a radius of $\sim6.5$ pc. We also report the detection of hot dust ($\sim 1000$ K) out to a nuclear distance of 80 pc measured along the semi-major axis., Comment: 14 pages

We present an empirical relation between the cold gas surface density ($\Sigma_{\rm gas}$) and the optical extinction (${\rm A_V}$) 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 $\Sigma_{\rm gas}$-${\rm A_V}$ relation on global, radial, and kpc (spaxel) scales. We determine ${\rm A_V}$ from the Balmer decrement (H$\alpha$/H$\beta$). We find that the best fit for this relation is $\Sigma_{\rm gas} ({\rm M_\odot pc^{-2}})\sim~26~\times~ {\rm A_V}({\rm mag})$, 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 $\Sigma_{\rm gas}$/ ${\rm A_V}$ ratio on radial and spaxel scales as a function of ${\rm EW(H\alpha)}$. We find that at larger values of ${\rm EW(H\alpha)}$ (i.e., actively star-forming regions) this ratio tend to converge to the value expected for dust-star mixed geometries ($\sim$ 30 $\mathrm{M_{\odot} \,pc^{-2}\,mag^{-1}}$). On radial scales, we do not find a significant relation between the $\Sigma_{\rm gas}$/${\rm A_V}$ ratio and the ionized gas metallicity. We contrast our estimates of $\Sigma_{\rm gas}$ using ${\rm A_V}$ 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 $\Sigma_{\rm gas}$-$\Sigma_*$ relation. These tests show that optical extinction is a reliable proxy for estimating $\Sigma_{\rm gas}$ in the absence of direct sub/millimeter observations of the cold gas., Comment: 12 pages, 10 figures. Submitted to MNRAS

We present a near-infrared study of the Seyfert 2 galaxy NGC\,6300, based on subarcsecond images and long slit spectroscopy obtained with Flamingos-2 at Gemini South. We have found that the peak of the nuclear continuum emission in the $K_s$ band and the surrounding nuclear disk are 25\,pc off-center with respect to the center of symmetry of the larger scale circumnuclear disk, suggesting that this black hole is still not fixed in the galaxy potential well. The molecular gas radial velocity curve yields a central black hole upper mass estimation of $M_{SMBH}^{upper}=(6\pm 2) \times 10^{7}\,\Msun$. The Pa$\beta$ emission line has a strongly asymmetric profile with a blueshifted broad component that we associate with a nuclear ionized gas outflow. We have found in the $K_s$-band spectra that the slope of the continuum becomes steeper with increasing radii, which can be explained as the presence of large amounts of hot dust not only in the nucleus but also in the circumnuclear region up to $r=27$\,pc. In fact, the nuclear red excess obtained after subtracting the stellar contribution resembles to that of a blackbody with temperatures around 1200\,K. This evidence supports the idea that absorbing material located around the nucleus, but not close enough to be the torus of the unified model, could be responsible for at least part of the nuclear obscuration in this Seyfert 2 nucleus.

We present a near-infrared study of the Seyfert 2 galaxy NGC\,6300, based on subarcsecond images and long slit spectroscopy obtained with Flamingos-2 at Gemini South. We have found that the peak of the nuclear continuum emission in the $K_s$ band and the surrounding nuclear disk are 25\,pc off-center with respect to the center of symmetry of the larger scale circumnuclear disk, suggesting that this black hole is still not fixed in the galaxy potential well. The molecular gas radial velocity curve yields a central black hole upper mass estimation of $M_{SMBH}^{upper}=(6\pm 2) \times 10^{7}\,\Msun$. The Pa$\beta$ emission line has a strongly asymmetric profile with a blueshifted broad component that we associate with a nuclear ionized gas outflow. We have found in the $K_s$-band spectra that the slope of the continuum becomes steeper with increasing radii, which can be explained as the presence of large amounts of hot dust not only in the nucleus but also in the circumnuclear region up to $r=27$\,pc. In fact, the nuclear red excess obtained after subtracting the stellar contribution resembles to that of a blackbody with temperatures around 1200\,K. This evidence supports the idea that absorbing material located around the nucleus, but not close enough to be the torus of the unified model, could be responsible for at least part of the nuclear obscuration in this Seyfert 2 nucleus.

We present an empirical relation between the cold gas surface density ($\Sigma_{\rm gas}$) and the optical extinction (${\rm A_V}$) 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 $\Sigma_{\rm gas}$-${\rm A_V}$ relation on global, radial, and kpc (spaxel) scales. We determine ${\rm A_V}$ from the Balmer decrement (H$\alpha$/H$\beta$). We find that the best fit for this relation is $\Sigma_{\rm gas} ({\rm M_\odot pc^{-2}})\sim~26~\times~ {\rm A_V}({\rm mag})$, 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 $\Sigma_{\rm gas}$/ ${\rm A_V}$ ratio on radial and spaxel scales as a function of ${\rm EW(H\alpha)}$. We find that at larger values of ${\rm EW(H\alpha)}$ (i.e., actively star-forming regions) this ratio tend to converge to the value expected for dust-star mixed geometries ($\sim$ 30 $\mathrm{M_{\odot} \,pc^{-2}\,mag^{-1}}$). On radial scales, we do not find a significant relation between the $\Sigma_{\rm gas}$/${\rm A_V}$ ratio and the ionized gas metallicity. We contrast our estimates of $\Sigma_{\rm gas}$ using ${\rm A_V}$ 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 $\Sigma_{\rm gas}$-$\Sigma_*$ relation. These tests show that optical extinction is a reliable proxy for estimating $\Sigma_{\rm gas}$ in the absence of direct sub/millimeter observations of the cold gas., Comment: 12 pages, 10 figures. Submitted to MNRAS

We present a comparative study of molecular and ionized gas kinematics in nearby galaxies. These results are based on observations from the EDGE survey, which measured spatially resolved $^{12}$CO(J=1-0) in 126 nearby galaxies. Every galaxy in EDGE has corresponding resolved ionized gas measurements from CALIFA. Using a sub-sample of 17 rotation dominated, star-forming galaxies where precise molecular gas rotation curves could be extracted, we derive CO and H$\alpha$ rotation curves using the same geometric parameters out to $\gtrsim$1 $R_e$. We find that $\sim$75% of our sample galaxies have smaller ionized gas rotation velocities than the molecular gas in the outer part of the rotation curve. In no case is the molecular gas rotation velocity measurably lower than that of the ionized gas. We suggest that the lower ionized gas rotation velocity can be attributed to a significant contribution from extraplanar diffuse ionized gas in a thick, turbulence supported disk. Using observations of the H$\gamma$ transition also available from CALIFA, we measure ionized gas velocity dispersions and find that these galaxies have sufficiently large velocity dispersions to support a thick ionized gas disk. Kinematic simulations show that a thick disk with a vertical rotation velocity gradient can reproduce the observed differences between the CO and H$\alpha$ rotation velocities. Observed line ratios tracing diffuse ionized gas are elevated compared to typical values in the midplane of the Milky Way. In galaxies affected by this phenomenon, dynamical masses measured using ionized gas rotation curves will be systematically underestimated., Comment: 37 pages, 18 figures, accepted for publication in ApJ

We present a comparative study of molecular and ionized gas kinematics in nearby galaxies. These results are based on observations from the EDGE survey, which measured spatially resolved $^{12}$CO(J=1-0) in 126 nearby galaxies. Every galaxy in EDGE has corresponding resolved ionized gas measurements from CALIFA. Using a sub-sample of 17 rotation dominated, star-forming galaxies where precise molecular gas rotation curves could be extracted, we derive CO and H$\alpha$ rotation curves using the same geometric parameters out to $\gtrsim$1 $R_e$. We find that $\sim$75% of our sample galaxies have smaller ionized gas rotation velocities than the molecular gas in the outer part of the rotation curve. In no case is the molecular gas rotation velocity measurably lower than that of the ionized gas. We suggest that the lower ionized gas rotation velocity can be attributed to a significant contribution from extraplanar diffuse ionized gas in a thick, turbulence supported disk. Using observations of the H$\gamma$ transition also available from CALIFA, we measure ionized gas velocity dispersions and find that these galaxies have sufficiently large velocity dispersions to support a thick ionized gas disk. Kinematic simulations show that a thick disk with a vertical rotation velocity gradient can reproduce the observed differences between the CO and H$\alpha$ rotation velocities. Observed line ratios tracing diffuse ionized gas are elevated compared to typical values in the midplane of the Milky Way. In galaxies affected by this phenomenon, dynamical masses measured using ionized gas rotation curves will be systematically underestimated., Comment: 37 pages, 18 figures, accepted for publication in ApJ

We present interferometric CO observations made with the Combined Array for Millimeter-wave Astronomy (CARMA) 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 (3$\sigma$ sensitivity $\Sigma_{\rm mol}$ $\sim$ 11 M$_\odot$ pc$^{-2}$ before inclination correction, resolution $\sim1.4$ kpc) for 126 galaxies, constituting the largest interferometric CO survey of galaxies in the nearby universe. We describe the survey, the data characteristics, the data products, and 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, present preliminary results on the resolved relations between the molecular gas, stars, and star formation rate, and discuss the dependence of the resolved molecular depletion time on stellar surface density, nebular extinction, and gas metallicity. EDGE provides a key dataset 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., Comment: Accepted by ApJ, 50 pp including figures

We present interferometric CO observations made with the Combined Array for Millimeter-wave Astronomy (CARMA) 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 (3$\sigma$ sensitivity $\Sigma_{\rm mol}$ $\sim$ 11 M$_\odot$ pc$^{-2}$ before inclination correction, resolution $\sim1.4$ kpc) for 126 galaxies, constituting the largest interferometric CO survey of galaxies in the nearby universe. We describe the survey, the data characteristics, the data products, and 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, present preliminary results on the resolved relations between the molecular gas, stars, and star formation rate, and discuss the dependence of the resolved molecular depletion time on stellar surface density, nebular extinction, and gas metallicity. EDGE provides a key dataset 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., Comment: Accepted by ApJ, 50 pp including figures

We study, for the first time in a statistically significant and well-defined sample, the relation between the outer-disk ionized-gas metallicity gradients and the presence of breaks in the surface brightness profiles of disk galaxies. Sloan Digital Sky Survey (SDSS) g′- and r′-band surface brightness, (g′ - r′) color, and ionized-gas oxygen abundance profiles for 324 galaxies within the Calar Alto Legacy Integral Field Area (CALIFA) survey are used for this purpose. We perform a detailed light-profile classification, finding that 84% of our disks show down- or up-bending profiles (Type II and Type III, respectively), while the remaining 16% are well fitted by one single exponential (Type I). The analysis of the color gradients at both sides of this break shows a U-shaped profile for most Type II galaxies with an average minimum (g′ - r′) color of ∼ 0.5mag and an ionized-gas metallicity flattening associated with it only in the case of low-mass galaxies. Comparatively, more massive systems show a rather uniform negative metallicity gradient. The correlation between metallicity flattening and stellar mass for these systems results in p-values as low as 0.01. Independent of the mechanism having shaped the outer light profiles of these galaxies, stellar migration or a previous episode of star formation in a shrinking star-forming disk, it is clear that the imprint in their ionized-gas metallicity was different for low- and high-mass Type II galaxies. In the case of Type III disks, a positive correlation between the change in color and abundance gradient is found (the null hypothesis is ruled out with a p-value of 0.02), with the outer disks of Type III galaxies with masses ≤10 M′ showing a weak color reddening or even a bluing. This is interpreted as primarily due to a mass downsizing effect on the population of Type III galaxies that recently experienced an enhanced inside-out growth.

The final product of galaxy evolution through cosmic time is the population of galaxies in the local universe. These galaxies are also those that can be studied in most detail, thus providing a stringent benchmark for our understanding of galaxy evolution. Through the huge success of spectroscopic single-fiber, statistical surveys of the Local Universe in the last decade, it has become clear, however, that an authoritative observational description of galaxies will involve measuring their spatially resolved properties over their full optical extent for a statistically significant sample. We present here the Calar Alto Legacy Integral Field Area (CALIFA) survey, which has been designed to provide a first step in this direction. We summarize the survey goals and design, including sample selection and observational strategy. We also showcase the data taken during the first observing runs (June/July 2010) and outline the reduction pipeline, quality control schemes and general characteristics of the reduced data. This survey is obtaining spatially resolved spectroscopic information of a diameter selected sample of ∼600 galaxies in the Local Universe (0.005 < z < 0.03). CALIFA has been designed to allow the building of two-dimensional maps of the following quantities: (a) stellar populations: ages and metallicities; (b) ionized gas: distribution, excitation mechanism and chemical abundances; and (c) kinematic properties: both from stellar and ionized gas components. CALIFA uses the PPAK integral field unit (IFU), with a hexagonal field-of-view of ∼1.3 ′, with a 100% covering factor by adopting a three-pointing dithering scheme. The optical wavelength range is covered from 3700 to 7000 Å, using two overlapping setups (V500 and V1200), with different resolutions: R ∼ 850 and R ∼ 1650, respectively. CALIFA is a legacy survey, intended for the community. The reduced data will be released, once the quality has been guaranteed. The analyzed data fulfillthe expectations of the o

The final product of galaxy evolution through cosmic time is the population of galaxies in the local universe. These galaxies are also those that can be studied in most detail, thus providing a stringent benchmark for our understanding of galaxy evolution. Through the huge success of spectroscopic single-fiber, statistical surveys of the Local Universe in the last decade, it has become clear, however, that an authoritative observational description of galaxies will involve measuring their spatially resolved properties over their full optical extent for a statistically significant sample. We present here the Calar Alto Legacy Integral Field Area (CALIFA) survey, which has been designed to provide a first step in this direction. We summarize the survey goals and design, including sample selection and observational strategy. We also showcase the data taken during the first observing runs (June/July 2010) and outline the reduction pipeline, quality control schemes and general characteristics of the reduced data. This survey is obtaining spatially resolved spectroscopic information of a diameter selected sample of ∼600 galaxies in the Local Universe (0.005 < z < 0.03). CALIFA has been designed to allow the building of two-dimensional maps of the following quantities: (a) stellar populations: ages and metallicities; (b) ionized gas: distribution, excitation mechanism and chemical abundances; and (c) kinematic properties: both from stellar and ionized gas components. CALIFA uses the PPAK integral field unit (IFU), with a hexagonal field-of-view of ∼1.3 ′, with a 100% covering factor by adopting a three-pointing dithering scheme. The optical wavelength range is covered from 3700 to 7000 Å, using two overlapping setups (V500 and V1200), with different resolutions: R ∼ 850 and R ∼ 1650, respectively. CALIFA is a legacy survey, intended for the community. The reduced data will be released, once the quality has been guaranteed. The analyzed data fulfillthe expectations of the o