Abstract
We present an extensive exploration of the impact of 29 physical parameters in the oxygen abundance for a sample of 299 star-forming galaxies extracted from the extended Calar Alto Legacy ...Integral Field Area Survey sample. We corroborate that the stellar mass is the physical parameter that better traces the observed oxygen abundance (i.e., the mass–metallicity relation; MZR), while other physical parameters could play a potential role in shaping this abundance, but with a lower significant impact. We find that the functional form that best describes the MZR is a third-order polynomial function. From the residuals between this best functional form and the MZR, we find that once considered the impact of the mass in the oxygen abundance, the other physical parameters do not play a significant secondary role in shaping the oxygen abundance in these galaxies (including the gas fraction or the star formation rate). Our analysis suggests that the origin of the MZR is related to the chemical enrichment evolution of the interstellar medium due, most likely, to the buildup of stellar mass in these star-forming galaxies.
We present a study of the H ii regions in the galaxy NGC 6754 from a two pointing mosaic comprising 197 637 individual spectra, using integral field spectroscopy recently acquired with the MUSE ...instrument during its Science Verification program. The data cover the entire galaxy out to ~2 effective radii (re), sampling its morphological structures with unprecedented spatial resolution for a wide-field Integral Field Unit. A complete census of the H ii regions limited by the atmospheric seeing conditions was derived, comprising 396 individual ionized sources. This is one of the largest and most complete catalogues of H ii regions with spectroscopic information in a single galaxy. We use this catalogue to derive the radial abundance gradient in this SBb galaxy, finding a negative gradient with a slope consistent with the characteristic value for disk galaxies recently reported. The large number of H ii regions allows us to estimate the typical mixing scale length (rmix ~ 0.4re), which sets strong constraints on the proposed mechanisms for metal mixing in disk galaxies, like radial movements associated with bars and spiral arms. We found evidence of an azimuthal variation in the oxygen abundance that may be connected with the radial migration. These results illustrate the unique capabilities of MUSE for the study of the enrichment mechanisms in Local Universe galaxies.
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We report the detection of a highly collimated linear emission-line structure in the spiral galaxy NGC 232 through the use of integral field spectroscopy data from the All-weather MUse Supernova ...Integral field Nearby Galaxies survey. This jet-like feature extends radially from the nucleus and is primarily detected in O iiiλ5007 without clear evidence of an optical continuum counterpart. The length of the radial structure projected on sky reaches ∼3 kpc, which makes NGC 232 the second-longest emission-line jet reported. The ionized gas presents extreme O iii/Hβ and N ii/H line ratios, increasing along the jet-like structure. We discuss three possible scenarios to explain the observed structure: (i) direct ionization of infalling material from the intergalactic medium by the AGN, (ii) photoionization by an undetected optical counterpart of the radio jet, and (iii) fast shock ionization due to the lateral expansion of the radio jet across the interstellar medium. Our analysis favors in situ ionization.
Ionized gas kinematics provide important clues to the dynamical structure of galaxies and hold constraints to the processes driving their evolution. The motivation of this work is to provide an ...overall characterization of the kinematic behavior of the ionized gas of the galaxies included in the Calar Alto Legacy Integral field Area (CALIFA), offering kinematic clues to potential users of the CALIFA survey for including kinematical criteria in their selection of targets for specific studies. From the first 200 galaxies observed by CALIFA survey in its two configurations, we present the two-dimensional kinematic view of the 177 galaxies satisfaying a gas content/detection threshold. This work constitutes the first determination of the ionized gas kinematics of the galaxies observed in the CALIFA survey. The derived velocity fields, the reported kinematic distortions/peculiarities and the identification of the presence of several gaseous components in different regions of the objects might be used as additional criteria for selecting galaxies for specific studies.
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Abstract
One way the active galactic nuclei (AGN) are expected to influence the evolution of their host galaxies is by removing metal content via outflows. In this article we present results that ...show that AGN can have an effect on the chemical enrichment of their host galaxies using the fossil record technique on CALIFA galaxies. We classified the chemical enrichment histories of all galaxies in our sample regarding whether they show a drop in the value of their metallicity. We find that galaxies currently hosting an AGN are more likely to show this drop in their metal content compared to the quiescent sample. Once we separate the sample by their star-forming status we find that star-forming galaxies are less likely to have a drop in metallicity but have deeper decreases when these appear. This behavior could be evidence for the influence of either pristine gas inflows or galactic outflows triggered by starbursts, both of which can produce a drop in metallicity.
We use the stellar kinematics for 2458 galaxies from the MaNGA survey to explore a universal fundamental plane (UFP) described by the equation , defined by the logarithms of effective radius, Re; the ...surface brightness within Re, Ie; the dynamical mass-to-light ratio within Re, Ye; and the total velocity parameter at Re, , where is the rotation velocity and is the velocity dispersion. The surface brightness is within Re, Ie, and the dynamical mass-to-light ratio is within Re, e. We use sophisticated Schwarzschild dynamical models for a subsample of 300 galaxies from the CALIFA survey to calibrate the universal fundamental plane. This calibration allows us to propose both (i) a parameterization to estimate the difficult-to-measure averaged dynamical mass-to-light ratio within Re, , once the internal kinematics, surface brightness, and effective radius are known; and (ii) a new, more robust dynamical mass proxy consistent with dynamical models within 0.09 dex. We reproduce the relation between the dynamical mass and the stellar mass in the inner regions of galaxies with lower scatter. We use the estimated from our analysis to explore the UFP with the MaNGA data set. We find that all galaxies, from spheroids to disks, follow the UFP with a scatter significantly smaller (0.05 dex) than the one reported for the fundamental plane (∼0.09 dex) and comparable with Tully-Fisher studies (∼0.05 dex), but for a wider range of galaxy types. We also confirm that spheroidal and spiral galaxies follow the same M -S0.5 scaling relation, with lower scatter than the and ones, which is in agreement with previous studies found in the literature.
Star-formation is one of the main processes that shape galaxies, defining its stellar population and metallicity production and enrichment. It is nowadays known that this process is ruled by a set of ...relations that connect three parameters: the molecular gas mass, the stellar mass and the star-formation rate itself. These relations are fulfilled at a wide range of scales in galaxies, from galaxy wide to kpc-scales. At which scales they are broken, and how universal they are (i.e., if they change at different scales or for different galaxy types) it is still an open question. We explore here how those relations compare at different scales using as proxy the new analysis done using Integral Field Spectroscopy data and CO observations data from the EDGE-CALIFA survey and the AMUSSING++ compilation.
Abstract
The diagram comparing the flux ratio of the O
iii
and H
β
emission lines with the total stellar mass of galaxies (also known as the mass-excitation diagram, MEx) has been widely used to ...classify the ionization mechanism in high redshift galaxies, dividing star-forming galaxies from those where active galactic nuclei are important. This diagram was mainly derived using single-fiber spectroscopy from the SDSS-DR7 survey. In this study, we revise this diagram using the central and integrated spectral measurement from the entire Integral Field Spectroscopic MaNGA sample. Our results suggest that along with these physical parameters, the equivalent width of the H
α
emission line is also required to constrain the ionization mechanism of a high-redshifted galaxy. Furthermore, the location of a galaxy in the excitation-mass diagram varies depending on the use of central or integrated properties.
Abstract
We use the stellar kinematics for 2458 galaxies from the MaNGA survey to explore a universal fundamental plane (UFP) described by the equation
, defined by the logarithms of effective ...radius,
R
e
; the surface brightness within Re,
I
e
; the dynamical mass-to-light ratio within
R
e
,
Y
e
; and the total velocity parameter at
R
e
,
, where
is the rotation velocity and
is the velocity dispersion. The surface brightness is within
R
e
,
I
e
, and the dynamical mass-to-light ratio is within
R
e
, ϒ
e
. We use sophisticated Schwarzschild dynamical models for a subsample of 300 galaxies from the CALIFA survey to calibrate the universal fundamental plane. This calibration allows us to propose both (i) a parameterization to estimate the difficult-to-measure averaged dynamical mass-to-light ratio within
R
e
,
, once the internal kinematics, surface brightness, and effective radius are known; and (ii) a new, more robust dynamical mass proxy consistent with dynamical models within 0.09 dex. We reproduce the relation between the dynamical mass and the stellar mass in the inner regions of galaxies with lower scatter. We use the estimated
from our analysis to explore the UFP with the MaNGA data set. We find that all galaxies, from spheroids to disks, follow the UFP with a scatter significantly smaller (0.05 dex) than the one reported for the fundamental plane (∼0.09 dex) and comparable with Tully–Fisher studies (∼0.05 dex), but for a wider range of galaxy types. We also confirm that spheroidal and spiral galaxies follow the same
M
⋆
–
S
0.5
scaling relation, with lower scatter than the
and
ones, which is in agreement with previous studies found in the literature.
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