scholarly journals Studying the Interstellar Medium of H II/BCD Galaxies Using IFU Spectroscopy

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Patricio Lagos ◽  
Polychronis Papaderos
Keyword(s):  
Interstellar Medium ◽  
Physical Properties ◽  
Starburst Galaxies ◽  
Chemical Abundances ◽  
Spatially Resolved ◽  
Low Mass ◽  
Field Unit ◽  
Integral Field

We review the results from our studies, and previous published work, on the spatially resolved physical properties of a sample of Hii/BCD galaxies, as obtained mainly from integral-field unit spectroscopy with Gemini/GMOS and VLT/VIMOS. We confirm that, within observational uncertainties, our sample galaxies show nearly spatially constant chemical abundances similar to other low-mass starburst galaxies. They also show Heii  λ4686 emission with the properties being suggestive of a mix of excitation sources and with Wolf-Rayet stars being excluded as the primary ones. Finally, in this contribution, we include a list of all Hii/BCD galaxies studied thus far with integral-field unit spectroscopy.

scholarly journals Capturing the Physics of MaNGA Galaxies with Self-supervised Machine Learning

2021 ◽  
Vol 921 (2) ◽  
pp. 177
Author(s):  
Regina Sarmiento ◽  
Marc Huertas-Company ◽  
Johan H. Knapen ◽  
Sebastián F. Sánchez ◽  
Helena Domínguez Sánchez ◽  
...  
Keyword(s):  
Machine Learning ◽  
Physical Properties ◽  
Supervised Machine Learning ◽  
Data Sets ◽  
Complex Data ◽  
Galaxy Surveys ◽  
Complex Data Sets ◽  
Low Mass ◽  
Field Unit ◽  
Integral Field

Abstract As available data sets grow in size and complexity, advanced visualization tools enabling their exploration and analysis become more important. In modern astronomy, integral field spectroscopic galaxy surveys are a clear example of increasing high dimensionality and complex data sets, which challenges the traditional methods used to extract the physical information they contain. We present the use of a novel self-supervised machine-learning method to visualize the multidimensional information on stellar population and kinematics in the MaNGA survey in a 2D plane. Our framework is insensitive to nonphysical properties such as the size of the integral field unit and is therefore able to order galaxies according to their resolved physical properties. Using the extracted representations, we study how galaxies distribute based on their resolved and global physical properties. We show that even when exclusively using information about the internal structure, galaxies naturally cluster into two well-known categories, rotating main-sequence disks and massive slow rotators, from a purely data-driven perspective, hence confirming distinct assembly channels. Low-mass rotation-dominated quenched galaxies appear as a third cluster only if information about the integrated physical properties is preserved, suggesting a mixture of assembly processes for these galaxies without any particular signature in their internal kinematics that distinguishes them from the two main groups. The framework for data exploration is publicly released with this publication, ready to be used with the MaNGA or other integral field data sets.

scholarly journals Chemical abundances in Seyfert galaxies – V. The discovery of shocked emission outside the AGN ionization axis

2020 ◽  
Vol 501 (1) ◽  
pp. L54-L59
Author(s):  
R A Riffel ◽  
O L Dors ◽  
M Armah ◽  
T Storchi-Bergmann ◽  
A Feltre ◽  
...  
Keyword(s):  
Electron Temperature ◽  
Active Galactic Nuclei ◽  
Direct Evidence ◽  
Galactic Nuclei ◽  
Seyfert Galaxies ◽  
Chemical Abundances ◽  
Temperature Distributions ◽  
Field Unit ◽  
Dusty Torus ◽  
Integral Field

ABSTRACT We present maps for the electron temperature in the inner kpc of three luminous Seyfert galaxies: Mrk 79, Mrk 348, and Mrk 607 obtained from Gemini Multi-Object Spectrograph-integral field unit observations at spatial resolutions of ∼110–280 pc. We study the distributions of electron temperature in active galaxies and find temperatures varying in the range from ∼8000 to $\gtrsim 30\, 000\,$K. Shocks due to gas outflows play an important role in the observed temperature distributions of Mrk 79 and Mrk 348, while standard photoionization models reproduce the derived temperature values for Mrk 607. In Mrk 79 and Mrk 348, we find direct evidence for shock ionization with overall orientation orthogonal to the ionization axis, where shocks can be easily observed as the active galactic nuclei radiation field is shielded by the nuclear dusty torus. This also indicates that even when the ionization cones are narrow, the shocks can be much wider angle.

scholarly journals Spatially resolved Lyman-alpha emission from a virtual dwarf galaxy

2014 ◽  
Vol 10 (S309) ◽  
pp. 295-296
Author(s):  
Anne Verhamme
Keyword(s):  
Second Generation ◽  
Dwarf Galaxy ◽  
Spatial Variations ◽  
Lyman Alpha ◽  
Spatially Resolved ◽  
Alpha Emission ◽  
Field Unit ◽  
Integral Field

AbstractIn the context of the first light of MUSE, Integral Field Unit (IFU) spectrograph of second generation installed recently at VLT, we compute mock IFU Lyman-alpha (lyα) observations of a virtual dwarf galaxy, to help understanding and interpreting forthcoming observations. This study is an extension of the work carried out in Verhamme et al. (2012), where we studied the spatially integrated lyα properties of a dwarf galaxy. With the same data, we now investigate the spatial variations of lyα spectra.

scholarly journals Integral field observations of distant cluster galaxies

2006 ◽  
Vol 2 (S237) ◽  
pp. 489-489
Author(s):  
D. Vergani ◽  
C. Balkowski ◽  
H. Flores ◽  
V. Cayatte ◽  
F. Hammer ◽  
...  
Keyword(s):  
Structural Parameters ◽  
High Angular Resolution ◽  
Cluster Galaxies ◽  
Spatially Resolved ◽  
Optical Images ◽  
Local Measurements ◽  
Fisher Relation ◽  
Field Unit ◽  
Stellar Masses ◽  
Integral Field

AbstractWe have used the FLAMES multi-integral field unit system of the European Southern Observatory (VLT) centered on the cluster MS0451.6-0305 at z = 0.5386 to obtain the spatially resolved kinematics of the cluster members. The spectral data are supported by HST/ACS images that provide immediate morphological information of the cluster galaxies. The relevant structural parameters such as inclination, size, and orientation derived from optical high angular resolution images are compared with those derived from the kinematics. Our final goals are: 1. to derive the Tully-Fisher relation for cluster galaxies with regular kinematics. 2. to obtain the dynamical masses from resolved kinematics and stellar masses from optical images to be compared with local measurements.

scholarly journals Optical SED models of galaxy mergers

2011 ◽  
Vol 7 (S284) ◽  
pp. 193-197
Author(s):  
Gregory F. Snyder ◽  
T. J. Cox ◽  
Christopher C. Hayward ◽  
Lars Hernquist ◽  
Patrik Jonsson
Keyword(s):  
Three Dimensional ◽  
Interacting Galaxies ◽  
Galaxy Mergers ◽  
Hydrodynamic Simulations ◽  
Spatially Resolved ◽  
Multi Wavelength ◽  
Field Unit ◽  
Effects Of Feedback ◽  
Dust Attenuation ◽  
Integral Field

AbstractI discuss recent work in which we construct models of poststarburst galaxies by combining fully three-dimensional hydrodynamic simulations of galaxy mergers with radiative transfer calculations of dust attenuation. The poststarburst signatures can occur shortly after a bright starburst phase in gas-rich mergers, and thus offer a unique opportunity to study the formation of bulges and the effects of feedback. Several additional applications of spatially-resolved spectroscopic models of interacting galaxies include multi-wavelength studies of AGN/starburst diagnostics, mock integral field unit data to interpret the evolution of ULIRGs, and the ‘Green Valley’.Optical spectra of simulated major gas-rich galaxy mergers can be found at http://www.cfa.harvard.edu/~gsnyder

scholarly journals SDSS-IV MaNGA: Observational Evidence of a Density-bounded Region in a Lyα Emitter

2022 ◽  
Vol 924 (2) ◽  
pp. 47
Author(s):  
Abhishek Paswan ◽  
Kanak Saha ◽  
Claus Leitherer ◽  
Daniel Schaerer
Keyword(s):  
Gas Phase ◽  
Observational Evidence ◽  
Moderate Correlation ◽  
Spatially Resolved ◽  
Lyman Continuum ◽  
The Galaxy ◽  
Field Unit ◽  
Dust Distribution ◽  
First Time ◽  
Integral Field

Abstract Using integral field unit spectroscopy, we present here the spatially resolved morphologies of [S ii]λ6717,6731/Hα and [S ii]λ6717,6731/[O iii]λ5007 emission line ratios for the first time in a blueberry Lyα emitter (BBLAE) at z ∼ 0.047. Our derived morphologies show that the extreme starburst region of the BBLAE, populated by young (≤10 Myr), massive Wolf–Rayet stars, is [S ii] deficient, while the rest of the galaxy is [S ii] enhanced. We infer that the extreme starburst region is density-bounded (i.e., optically thin to ionizing photons), and the rest of the galaxy is ionization-bounded, indicating a Blister-type morphology. We find that the previously reported small escape fraction (10%) of Lyα photons is from our identified density-bounded H ii region of the BBLAE. This escape fraction is likely constrained by a porous dust distribution. We further report a moderate correlation between [S ii] deficiency and inferred Lyman continuum (LyC) escape fraction using a sample of confirmed LyC leakers studied in the literature, including the BBLAE studied here. The observed correlation also reveals its dependency on the stellar mass and gas-phase metallicity of the leaky galaxies. Finally, the future scope and implications of our work are discussed in detail.

HCL1 and HCL2 - low mass star formation in violent and quiet environments

2018 ◽  
Vol 14 (S345) ◽  
pp. 333-334
Author(s):  
L. Viktor Tóth ◽  
Orsolya Fehér ◽  
Mika Juvela ◽  
Julien Montillaud ◽  
Sándor Pintér
Keyword(s):  
Star Formation ◽  
Interstellar Medium ◽  
Physical Properties ◽  
Mass Star ◽  
External Effects ◽  
Star Forming ◽  
Radio Line ◽  
Sky Survey ◽  
Low Mass

AbstractRecently a large number of Galactic cold clumps were located with the Planck all-sky survey. Our radio line observations have revealed the distribution and physical properties of the interstellar medium in dozens of PGCC sources. Clumps can be affected by many external effects. HCL1 (a.k.a. L1251) and HCL2 (which contains also TMC-1) are examples of low mass star forming clouds in violent and quiet environments.

Simulations of High-z Starburst Galaxies for the JWST-MIRI Integral Field Unit

2009 ◽  
pp. 33-36
Author(s):  
M. García-Marín ◽  
N.P.F Lorente ◽  
A. Glasse ◽  
L. Colina ◽  
G. Wright
Keyword(s):  
Starburst Galaxies ◽  
Field Unit ◽  
Integral Field

scholarly journals Exploring the differences of integrated and spatially resolved analysis using integral field unit data: the case of Abell 14

2020 ◽  
Vol 493 (2) ◽  
pp. 2238-2252 ◽  
Author(s):  
Stavros Akras ◽  
Hektor Monteiro ◽  
Isabel Aleman ◽  
Marcos A F Farias ◽  
Daniel May ◽  
...  
Keyword(s):  
Emission Line ◽  
Planetary Nebula ◽  
Three Dimensional ◽  
Position Angle ◽  
Type I ◽  
Ionization State ◽  
Chemical Abundances ◽  
Combining Data ◽  
Field Unit ◽  
Integral Field

ABSTRACT We present a new approach to study planetary nebulae using integral field spectroscopy. VLT@VIMOS datacube of the planetary nebula Abell 14 is analysed in three different ways by extracting: (i) the integrated spectrum, (ii) one-dimensional simulated long-slit spectra for different position angles, and (iii) spaxel-by-spaxel spectra. These data are used to build emission-line diagnostic diagrams and explore the ionization structure and excitation mechanisms combining data from one- and three-dimensional photoionization models. The integrated and 1D simulated spectra are suitable for developing diagnostic diagrams, while the spaxel spectra can lead to misinterpretation of the observations. We find that the emission-line ratios of Abell 14 are consistent with UV photoionised emission; however, there are some pieces of evidence of an additional thermal mechanism. The chemical abundances confirm its previous classification as a Type I planetary nebula, without spatial variation. We find, though, variation in the ionization correction factors as a function of the slit’s position angle. The star at the geometric centre of Abell 14 has an A5 spectral type with an effective temperature of Teff = 7909 ± 135 K and surface gravity log(g) = 1.4 ± 0.1 cm s−2. Hence, this star cannot be responsible for the ionization state of the nebula. Gaia parallaxes of this star yield distances between 3.6 and 4.5 kpc in good agreement with the distance derived from a three-dimensional photoionization modelling of Abell 14, indicating the presence of a binary system at the centre of the planetary nebula.

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