A5057485549- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Gamma-ray bursts and supernovae
- CCD and CMOS Imaging Sensors
- Astrophysical Phenomena and Observations
- Adaptive optics and wavefront sensing
- Calibration and Measurement Techniques
- Astronomical Observations and Instrumentation
- Astro and Planetary Science
- Solar and Space Plasma Dynamics
- Radio Astronomy Observations and Technology
- Astrophysics and Cosmic Phenomena
- Radiation Therapy and Dosimetry
- Spectroscopy and Laser Applications
- Planetary Science and Exploration
- Scientific Research and Discoveries
- Ionosphere and magnetosphere dynamics
- Geophysics and Gravity Measurements
- Particle Accelerators and Free-Electron Lasers
- Prostate Cancer Treatment and Research
- Mycotoxins in Agriculture and Food
- Particle accelerators and beam dynamics
- Space Science and Extraterrestrial Life
Stockholm University
2013-2024
AlbaNova
2013-2024
University of Oslo
2017-2021
University of Copenhagen
2013
We present high-resolution far-UV spectroscopy of the 14 galaxies Lyman Alpha Reference Sample; a sample strongly star-forming at low redshifts ($0.028 < z 0.18$). compare derived properties to global from multi band imaging and 21 cm HI interferometry single dish observations, as well archival optical SDSS spectra. Besides $\alpha$ line, spectra contain number metal absorption features allowing us probe kinematics neutral ISM evaluate depth covering fraction medium function line-of-sight...
The Lyman-alpha reference sample (LARS) is a program with the Hubble Space Telescope (HST) that provides of local universe laboratory galaxies in which to study astrophysics visibility and strength (Lya) line hydrogen. This article presents an overview survey, its selection function HST imaging observations. was selected from GALEX+SDSS catalogue at z=0.028-0.19, order allow Lya be captured combinations long pass filters Solar Blind Channel (SBC) HST/ACS. In addition, LARS utilises Halpha...
We present rest-frame ultraviolet and optical spectroscopy of the brightest lensed galaxy yet discovered, at redshift z = 2.4. This source reveals a characteristic, triple-peaked Lyman {\alpha} profile which has been predicted by various theoretical works but to our knowledge not unambiguously observed previously. The feature is well fit superposition two components: double-peak emerging from substantial radiative transfer, narrow, central component resulting directly escaping photons;...
Abstract We measure the gas-phase abundances of elements He, N, O, Ne, S, Ar, and Fe in an individual H ii region known to be leaking Lyman-continuum photons Sunburst Arc, a highly magnified galaxy at redshift z = 2.37. detect temperature-sensitive auroral lines [S ] λλ 4070, 4076, [O iii λ 4363, 6314, 7320, 7330, [Ne 3343 stacked spectrum five multiple images emitter (LCE), from which we directly electron temperature low-, intermediate-, high-ionization zones. also density-sensitive...
We report upon new results regarding the Lya output of galaxies, derived from Lyman alpha Reference Sample (LARS), focusing on Hubble Space Telescope imaging. For 14 galaxies we present intensity images in Lya, Halpha, and UV, maps Halpha/Hbeta, equivalent width (EW), Lya/Halpha. UV light profiles show they are well-fitted by S\'ersic profiles, but indices systematically lower than those (n approx 1-2 instead >~4). This reveals a general lack central concentration that is ubiquitous UV....
The quasar Q0918+1636 (z=3.07) has two intervening high-metallicity Damped Lyman-alpha Absorbers (DLAs) along the line of sight, at redshifts z=2.412 and 2.583. z=2.583 DLA is located a large impact parameter 16.2 kpc, despite this it very high metallicity (consistent with solar), substantial fraction H_2 molecules, dusty as inferred from reddened spectrum background QSO. [M/H]=-0.6 (based on ZnII SiII). In paper we present new observations interesting sightline. HST/WFC3 imaging was...
Abstract Extreme, young stellar populations are considered to be the primary contributor cosmic reionization. How Lyman continuum (LyC) escapes these galaxies remains highly elusive, and it is challenging observe this process in actual LyC emitters without resolving relevant physical scales. We investigate Sunburst Arc, a strongly lensed emitter at z = 2.37 that reveals an exceptionally small-scale (tens of parsecs) region high escape. The small (<100 pc) LyC-leaking has extreme...
We report the detection of a population Wolf-Rayet (WR) stars in Sunburst Arc, strongly gravitationally lensed galaxy at redshift z = 2.37. As brightest known galaxy, Arc has become an important cosmic laboratory for studying star and cluster formation, Lyman α (Ly ) radiative transfer, continuum (LyC) escape. Here, we present first results JWST/NIRSpec IFU observations focusing on stacked spectrum 12-fold imaged LyC-emitting (LCE) cluster. In agreement with previous studies, find that LCE...
Abstract As the nearest confirmed Lyman continuum (LyC) emitter, Haro 11 is an exceptional laboratory for studying LyC escape processes crucial to cosmic reionization. Our new Hubble Space Telescope/Cosmic Origins Spectrograph G130M/1055 observations of its three star-forming knots now reveal that observed originates in Knots B and C, with 903–912 Å luminosities 1.9 ± 1.5 × 10 40 erg s −1 0.9 0.7 , respectively. We derive local fractions f esc,912 = 3.4% 2.9% 5.1% 4.3% Starburst99 modeling...
A comprehensive set of optical and near-infrared (NIR) photometry spectroscopy is presented for the faint fast 2008ha-like supernova (SN) 2010ae. Contingent on adopted value host extinction, SN 2010ae reached a peak brightness -13.8 > M_V -15.3 mag, while modeling UVOIR light curve suggests it produced 0.003--0.007 M_sun (56)Ni, ejected 0.30--0.60 material, had an explosion energy 0.04--0.30x10^51 erg. The values these parameters are similar to peculiar 2008ha --for which we also present...
ABSTRACT We demonstrate how the stellar and nebular conditions in star-forming galaxies modulate emission spectral profile of H i Ly α line. examine net output, kinematics, particular blueshifted radiation, using spectroscopy from with Cosmic Origins Spectrograph on Hubble Space Telescope (HST), giving a sample 87 at redshift z = 0.05−0.44. contrast measurements properties ionized gas (from optical spectra) stars modelling). correlations unprecedented strength between escape fraction (and...
Context. The transport of Lyα photons in galaxies is a complex process and the conditions under which manage to escape from certain still investigation. Lyman alpha reference sample (LARS) 14 local star-forming galaxies, designed study detail relate it rest-frame UV optical emission.
Ionizing photons escape a lensed galaxy Young, hot stars emit ultraviolet radiation, which can ionize neutral gas. The first generation of converted most the intergalactic gas in Universe from to ionized form during epoch reionization less than billion years after Big Bang. Rivera-Thorsen et al. took advantage gravitational lensing system observe 12 images same star-forming region distant and determined fraction that into medium. Although this is younger reionization, results provide clues...
We present integral field spectroscopic observations with the Potsdam Multi Aperture Spectrophotometer of all 14 galaxies in $z\sim 0.1$ Lyman Alpha Reference Sample (LARS). produce 2D line sight velocity maps and dispersion from Balmer $\alpha$ (H$\alpha$) emission our data cubes. These trace spectral spatial properties LARS galaxies' intrinsic Ly$\alpha$ radiation field. show kinematic spatially registered onto Hubble Space Telescope H$\alpha$ (Ly$\alpha$) images. Only for individual a...
Low- and intermediate mass galaxies are widely discussed as cause of reionization at redshift $z\sim10-6$. However, observational proof that leaking ionizing radiation (Lyman continuum; LyC) is a currently ongoing challenge the list LyC emitting candidates still short. Tololo 1247-232 among those very few with recently reported leakage. We performed resolution ultraviolet (UV) spectroscopy Cosmic Origins Spectrograph (COS) onboard Hubble Space Telescope confirm emerging from 1247-232....
ABSTRACT We present spatially resolved Echelle spectroscopy of an intervening Mg ii–Fe ii–Mg i absorption-line system detected at zabs = 0.73379 towards the giant gravitational arc PSZ1 G311.65–18.48. The absorbing gas is associated with inclined disc-like star-forming galaxy, whose major axis aligned two arc-segments reported here. probe in absorption galaxy’s extended disc continuously, ≈3 kpc sampling, from its inner region out to 15× optical radius. detect strong ($W_0^{2796}\gt 0.3$Å)...
Understanding the production and escape of Lyman $\alpha$ (Ly$\alpha$) radiation from star-forming galaxies is a long standing problem in astrophysics. The ability to predict Ly$\alpha$ luminosity would open up new ways exploring Epoch Reionization (EoR), estimate emission cosmological simulations where radiative transfer calculations cannot be done. We apply multivariate regression methods Alpha Reference Sample dataset obtain relation between galaxy properties emitted Ly$\alpha$. derived...
We analyze spectra of a gravitationally lensed galaxy, known as the Sunburst Arc, that is leaking ionizing photons, also Lyman continuum (LyC). Magnification from gravitational lensing permits galaxy to be spatially resolved into one region leaks and several do not. Rest-frame ultraviolet optical Magellan target ten different regions along including six multiple images LyC region, well four not show emission. The rest-frame photon emitting reveal blue-shifted ($\Delta V$=27 km s$^{-1}$)...
Abstract We present a strong-lensing analysis of the cluster PSZ1 G311.65−18.48, based on Hubble Space Telescope imaging, archival VLT/MUSE spectroscopy, and Chandra X-ray data. This cool-core ( z = 0.443) lenses brightest lensed galaxy known, dubbed “Sunburst Arc” 2.3703), Lyman continuum (LyC) emitting multiply imaged 12 times. identify in this field 14 additional strongly galaxies to constrain strong-lens model report secure spectroscopic redshifts four them. measure projected core mass M...
Abstract We analyze the far-ultraviolet (1130−1770 Å rest frame) spectroscopy of 20 young (<50 Myr) and massive (>10 4 M ⊙ ) star clusters (YSCs) in 11 nearby star-forming galaxies. probe interstellar gas intervening along line sight, detecting several metal absorption lines a wide range ionization potentials, from 6.0 to 77.5 eV. Multiple-component Voigt fits are used study kinematics gas. find that nearly all targets sample feature outflowing 30 up 190 km s −1 , often both neutral...
We present new H i imaging and spectroscopy of the 14 UV-selected star-forming galaxies in Lyman Alpha Reference Sample (LARS), aimed for a detailed study processes governing production, propagation, escape Lyα photons. New spectroscopy, obtained with 100 m Green Bank Telescope (GBT), robustly detects spectral line 11 observed LARS (although profiles two are likely confused by other sources within GBT beam); three highest redshift not detected at our current sensitivity limits. The used to...
The peculiar object known as Godzilla resides within the gravitationally lensed Sunburst Arc at z=2.37. Despite being very bright, it appears in only one of twelve images source galaxy, exhibiting unusual spectroscopic properties that have not been found any other clumps. We use JWST's unique combination spatial resolution and sensitivity to propose a unified, coherent explanation physical nature Godzilla. measured fluxes kinematic rest-optical emission lines its surrounding regions. Using...