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 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 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.

Multiple Absorption Systems in the Lines of Sight to Quadruply Lensed Quasar H1413+1143 As a Probe of the Circumgalactic medium around Dwarf Galaxy

2018 ◽  
Vol 14 (S344) ◽  
pp. 305-308
Author(s):  
Katsuya Okoshi ◽  
Yosuke Minowa ◽  
Nobunari Kashikawa ◽  
Suzuka Koyamada ◽  
Toru Misawa
Keyword(s):  
Dwarf Galaxy ◽  
Absorption Lines ◽  
High Signal ◽  
Lyman Alpha ◽  
Chemical Enrichment ◽  
Spatially Resolved ◽  
Multiple Components ◽  
Noise Spectroscopy ◽  
Multiple Absorption ◽  
Circumgalactic Medium

AbstractWe present the first measurement of differences in MgII absorption strength in multiple intervening absorbers, which are also identified as (sub-)Damped Lyman alpha absorption systems, in the four spectra of the quadruply lensed quasar H1413+1143, often referred to the “Cloverleaf”, from highly spatial resolution and high signal-to-noise spectroscopy with an optical multi-mode spectrograph, the Kyoto tridimentional spectrograph II on board the Subaru telescope. The detection of significant MgII absorptions in multiple components in the spatially-resolved spectra suggests that chemical enrichment differs at least on scale of about 10 kpc within the separation of sightlines. For, a DLA system at redshift zabs = 1.66, the rest equivalent widths of MgII absorption lines change by factors up to 6, which is similar to those of HI absorption lines. This suggests that (inhomogeneous) cold absorbers which give rise to strong HI/MgII absorptions dwell on a scale within 10 kpc in the circumgalactic medium (CGM).

scholarly journals Resolved galactic superwinds reconstructed around their host galaxies at z > 3

2021 ◽  
Vol 504 (2) ◽  
pp. 2629-2657
Author(s):  
Mandy C Chen ◽  
Hsiao-Wen Chen ◽  
Max Gronke ◽  
Michael Rauch ◽  
Tom Broadhurst
Keyword(s):  
Imaging Spectroscopy ◽  
Resonant Scattering ◽  
Spatial Variations ◽  
Host Galaxies ◽  
Star Forming ◽  
Lyman Alpha ◽  
Gas Kinematics ◽  
Spatially Resolved ◽  
Star Forming Regions ◽  
Low Mass

ABSTRACT This paper presents a detailed analysis of two giant Lyman-alpha (Ly α) arcs detected near galaxies at z = 3.038 and z = 3.754 lensed by the massive cluster MACS 1206−0847 (z = 0.44). The Ly α nebulae revealed in deep MUSE observations exhibit a double-peaked profile with a dominant red peak, indicating expansion/outflowing motions. One of the arcs stretches over 1 arcmin around the cluster Einstein radius, resolving the velocity field of the line-emitting gas on kpc scales around three star-forming galaxies of 0.3–$1.6\, L_*$ at z = 3.038. The second arc spans 15 arcsec in size, roughly centred around two low-mass Ly α emitters of $\approx 0.03\, L_*$ at z = 3.754. All three galaxies in the z = 3.038 group exhibit prominent damped Ly α absorption (DLA) and several metal absorption lines, in addition to nebular emission lines such as $\hbox{He ii}$$\lambda \, 1640$ and C iii]λλ1906, 1908. Extended Ly α emission appears to emerge from star-forming regions with suppressed surface brightness at the centre of each galaxy. Significant spatial variations in the Ly α line profile are observed which, when unaccounted for in the integrated line, leads to biased constraints for the underlying gas kinematics. The observed spatial variations indicate the presence of a steep velocity gradient in a continuous flow of high column density gas from star-forming regions into a low-density halo environment. A detailed inspection of available galaxy spectra shows no evidence of AGN activity in the galaxies, and the observed Ly α signals are primarily explained by resonant scattering. The study presented in this paper shows that spatially resolved imaging spectroscopy provides the most detailed insights yet into the kinematics of galactic superwinds associated with star-forming galaxies.

SIFUS: SOAR integral field unit spectrograph

2003 ◽  
Author(s):  
Jacques R. D. Lepine ◽  
Antonio C. de Oliveira ◽  
Milito V. Figueredo ◽  
Bruno V. Castilho ◽  
Clemens Gneiding ◽  
...  
Keyword(s):  
Field Unit ◽  
Integral Field

scholarly journals Solar Irradiance Variability Due to Solar Flares Observed in Lyman-Alpha Emission

Solar Physics ◽  
2021 ◽  
Vol 296 (3) ◽  
Author(s):  
Ryan O. Milligan
Keyword(s):  
Solar Flares ◽  
Solar Spectrum ◽  
Neutral Hydrogen ◽  
Solar Limb ◽  
High Background ◽  
Superposed Epoch Analysis ◽  
Lyman Alpha ◽  
Alpha Emission ◽  
Epoch Analysis ◽  
Very High

AbstractAs the Lyman-alpha (Ly$\upalpha $ α ) line of neutral hydrogen is the brightest emission line in the solar spectrum, detecting increases in irradiance due to solar flares at this wavelength can be challenging due to the very high background. Previous studies that have focused on the largest flares have shown that even these extreme cases generate enhancements in Ly$\upalpha $ α of only a few percent above the background. In this study, a superposed-epoch analysis was performed on ≈8500 flares greater than B1 class to determine the contribution that they make to changes in the solar EUV irradiance. Using the peak of the 1 – 8 Å X-ray emission as a fiducial time, the corresponding time series of 3123 B- and 4972 C-class flares observed in Ly$\upalpha $ α emission by the EUV Sensor on the Geostationary Operational Environmental Satellite 15 (GOES-15) were averaged to reduce background fluctuations and improve the flare signal. The summation of these weaker events showed that they produced a 0.1 – 0.3% enhancement to the solar Ly$\upalpha $ α irradiance on average. For comparison, the same technique was applied to 453 M- and 31 X-class flares, which resulted in a 1 – 4% increase in Ly$\upalpha $ α emission. Flares were also averaged with respect to their heliographic angle to investigate any potential center-to-limb variation. For each GOES class, the relative enhancement in Ly$\upalpha $ α at the flare peak was found to diminish for flares that occurred closer to the solar limb due to the opacity of the line and/or foreshortening of the footpoints. One modest event included in the study, a C6.6 flare, exhibited an unusually high increase in Ly$\upalpha $ α of 7% that may have been attributed to a failed filament eruption. Increases of this magnitude have hitherto only been associated with a small number of X-class flares.

The DIVING3D Project: Analysis of the nuclear region of Early-type Galaxies

2020 ◽  
Vol 15 (S359) ◽  
pp. 454-456
Author(s):  
T. V. Ricci ◽  
J. E. Steiner ◽  
R. B. Menezes
Keyword(s):  
Emission Lines ◽  
H Ii Regions ◽  
Sample Type ◽  
Early Type ◽  
Integral Field Spectroscopy ◽  
Project Analysis ◽  
Line Region ◽  
Field Unit ◽  
Integral Field

AbstractIn this work, we present preliminary results regarding the nuclear emission lines of a statistically complete sample of 56 early-type galaxies that are part of the Deep Integral Field Spectroscopy View of Nuclei of Galaxies (DIVING3D) Project. All early type galaxies (ETGs) were observed with the Gemini Multi-Object Spectrograph Integral Field Unit (GMOS-IFU) installed on the Gemini South Telescope. We detected emission lines in 93% of the sample, mostly low-ionization nuclear emission-line region galaxies (LINERs). We did not find Transition Objects nor H II regions in the sample. Type 1 objects are seen in ∼23% of the galaxies.

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