Publications (57)
Stellar dynamics of blue compact galaxies: I. Decoupled star-gas kinematics in ESO 400-G43
G. Ostlin, R. J. Cumming, P. Amram +5
In this letter we present the first results from a program aimed at measuring the stellar kinematics of blue compact galaxies by observing the near-infrared Calcium triplet. We sho…
Lyman continuum leakage versus quenching with the James Webb Space Telescope: The spectral signatures of quenched star formation activity in reionization-epoch galaxies
C. Binggeli, E. Zackrisson, K. Pelckmans +3
In this paper, we study the effects of a recent drop in star formation rate (SFR) on the spectra of epoch of reionization (EoR) galaxies, and the resulting degeneracy with the spec…
EELT-HIRES the high-resolution spectrograph for the E-ELT
A. Marconi, P. Di Marcantonio, V. D'Odorico +70
The first generation of E-ELT instruments will include an optical-infrared High Resolution Spectrograph, conventionally indicated as EELT-HIRES, which will be capable of providing…
Pointing the James Webb Space Telescope through lensing clusters - can the first stars and galaxies be detected?
E. Zackrisson
The James Webb Space Telescope (JWST), scheduled for launch in 2014, is expected to revolutionize our understanding of the high-redshift Universe. Even so, many of the most interes…
Can the James Webb Space Telescope detect isolated population III stars?
C. -E. Rydberg, E. Zackrisson, P. Scott
Isolated population III stars are postulated to exist at approximately z=10-30 and may attain masses up to a few hundred solar masses. The James Webb Space telescope (JWST) is the…
Ionization processes in a local analogue of distant clumpy galaxies: VLT MUSE IFU spectroscopy and FORS deep images of the TDG NGC 5291N
J. Fensch, P. -A. Duc, P. M. Weilbacher +2
We present IFU observations with MUSE@VLT and deep imaging with FORS@VLT of a dwarf galaxy recently formed within the giant collisional HI ring surrounding NGC 5291. This TDG-like…
Detecting population III galaxies with HST and JWST
E. Zackrisson
A small fraction of the atomic-cooling halos assembling at z<15 may form out of minihalos that never experienced any prior star formation, and could in principle host small galaxie…
On quasar host galaxies as tests of non-cosmological redshifts
E. Zackrisson
Despite a general consensus in the astronomical community that all quasars are located at the distances implied by their redshifts, a number of observations still challenge this in…
Future mmVLBI Research with ALMA: A European vision
R. P. J. Tilanus, T. P. Krichbaum, J. A. Zensus +165
Very long baseline interferometry at millimetre/submillimetre wavelengths (mmVLBI) offers the highest achievable spatial resolution at any wavelength in astronomy. The anticipated…
Gravitational lensing as a probe of cold dark matter subhalos
E. Zackrisson, T. Riehm
In the cold dark matter scenario, dark matter halos are assembled hierarchically from smaller subunits. Some of these subunits are disrupted during the merging process, whereas oth…
Evidence for Environmentally Dependent Cluster Disruption in M83
N. Bastian, A. Adamo, M. Gieles +8
Using multi-wavelength imaging from the Wide Field Camera 3 on the Hubble Space Telescope we study the stellar cluster populations of two adjacent fields in the nearby face-on spir…
Extragalactic SETI: The Tully-Fisher relation as a probe of Dysonian astroengineering in disk galaxies
E. Zackrisson, P. Calissendorff, S. Asadi +1
If advanced extraterrestrial civilizations choose to construct vast numbers of Dyson spheres to harvest radiation energy, this could affect the characteristics of their host galaxi…
Detecting gravitationally lensed population III galaxies with the Hubble Space Telescope and the James Webb Space Telescope
E. Zackrisson, A. Zitrin, M. Trenti +6
Small galaxies consisting entirely of population III (pop III) stars may form at high redshifts, and could constitute one of the best probes of such stars. Here, we explore the pro…
The HST colours of high-redshift population III galaxies with strong Lyman alpha emission
E. Zackrisson, A. K. Inoue, C. -E. Rydberg +1
Population III galaxies, made partly or exclusively of metal-free stars, are predicted to exist at high redshifts and may produce very strong Lya emission. A substantial fraction o…
High-redshift microlensing and the spatial distribution of dark matter in the form of MACHOs
E. Zackrisson, T. Riehm
A substantial part of the dark matter of the Universe could be in the form of compact objects (MACHOs), detectable through gravitational microlensing effects as they pass through t…
Balmer breaks in simulated galaxies at z>6
C. Binggeli, E. Zackrisson, X. Ma +6
Photometric observations of the spectroscopically confirmed galaxy MACS1149-JD1 have indicated the presence of a prominent Balmer break in its spectral energy distri…
Stellar Clusters in M83: Formation, evolution, disruption and the influence of environment
N. Bastian, A. Adamo, M. Gieles +6
We study the stellar cluster population in two adjacent fields in the nearby, face-on spiral galaxy, M83, using WFC3/HST imaging. The clusters are selected through visual inspectio…
Strong lensing by subhalos in the dwarf-galaxy mass range I: Image separations
E. Zackrisson, T. Riehm, O. Moeller +2
The cold dark matter scenario predicts that a large number of dark subhalos should be located within the halo of each Milky-way sized galaxy. One tell-tale signature of such dark s…
The Age Distribution of Clusters in M83
E. Silva-Villa, A. Adamo, N. Bastian +2
In order to empirically determine the timescale and environmental dependence of stellar cluster disruption, we have undertaken an analysis of the unprecedented multi-pointing (seve…
The Minimum Halo Mass for Star Formation at z = 6 - 8
K. Finlator, M. K. M. Prescott, B. D. Oppenheimer +6
Recent analysis of strongly-lensed sources in the Hubble Frontier Fields indicates that the rest-frame UV luminosity function of galaxies at 6--8 rises as a power law down to $…
The temporal and spatial evolution of the starburst in ESO 338-IG04 as probed by its star clusters
G. Ostlin, E. Zackrisson, N. Bergvall +1
In this paper we use ultra-violet (UV) and optical HST photometry in five bands, and an extensive set of spectral evolutionary synthesis scenarios to investigate the age and masses…
The spectral evolution of the first Galaxies. III. Simulated James Webb Space Telescope spectra of reionization-epoch galaxies with Lyman continuum leakage
E. Zackrisson, C. Binggeli, K. Finlator +8
Using four different suites of cosmological simulations, we generate synthetic spectra for galaxies with different Lyman continuum escape fractions (fesc) at redshifts z=7-9, in th…
The Snapshot Hubble U-Band Cluster Survey (SHUCS) II. Star Cluster Population of NGC 2997
J. E. Ryon, A. Adamo, N. Bastian +6
We study the star cluster population of NGC 2997, a giant spiral galaxy located at 9.5 Mpc and targeted by the Snapshot Hubble U-band Cluster Survey (SHUCS). Combining our U-band i…
Strong Lensing by Subhalos in the Dwarf-Galaxy Mass Range II: Detection Probabilities
T. Riehm, E. Zackrisson, E. Mortsell +1
The dark halo substructures predicted by current cold dark matter simulations may in principle be detectable through strong-lensing image splitting of quasars on small angular scal…
Modelling the red halos of blue compact galaxies
E. Zackrisson, N. Bergvall, T. Marquart +2
Optical/near-IR broadband photometry of the halos of blue compact galaxies (BCGs) have revealed a very red spectral energy distribution, which cannot easily be reconciled with any…
The Brightest Young Star Clusters in NGC 5253
D. Calzetti, K. E. Johnson, A. Adamo +43
The nearby dwarf starburst galaxy NGC5253 hosts a number of young, massive star clusters, the two youngest of which are centrally concentrated and surrounded by thermal radio emiss…
First Statistical Study of Over 100 Magnified Stellar Events at Redshift with JWST
J. M. Palencia, Fengwu Sun, J. M. Diego +25
Highly magnified stars at cosmological distances () become detectable thanks to microlensing by intracluster stars near the critical curves of galaxy clusters. Multi…
The spectral evolution of the first galaxies. I. James Webb Space Telescope detection limits and color criteria for population III galaxies
E. Zackrisson, C. -E. Rydberg, D. Schaerer +2
The James Webb Space Telescope (JWST) is expected to revolutionize our understanding of the high-redshift Universe, and may be able to test the prediction that the first, chemicall…
Super star clusters in Haro 11: Properties of a very young starburst and evidence for a near-infrared flux excess
A. Adamo, G. Ostlin, E. Zackrisson +3
We have used multi-band imaging to investigate the nature of the extreme starburst environment in Haro 11 galaxy. The central starburst region has been observed in 8 HST wavebands…
SPICA as a probe of cosmic reionization
E. Zackrisson, A. K. Inoue
Current data indicate that the reionization of the Universe was complete by redshift z~6-7, and while the sources responsible for this process have yet to be identified, star-formi…
Star cluster formation and evolution in Mrk 930: properties of a metal-poor starburst
A. Adamo, G. Ostlin, E. Zackrisson +4
We present a HST multiband analysis of the large population of star clusters in the blue compact galaxy (BCG) Mrk 930. We have reconstructed the spectral energy distributions of th…
JWST spectroscopic confirmation of the Cosmic Gems arc at z=9.625 -- Insights into the small scale structure of a post-burst system
M. Messa, E. Vanzella, F. Loiacono +30
We present JWST/NIRSpec integral field spectroscopy of the Cosmic Gems arc, strongly magnified by the galaxy cluster SPT-CL J06155746. Six-hour integration using NIRSpec prism s…
A puzzling non-detection of [O III] and [C II] from a galaxy observed with ALMA
C. Binggeli, A. K. Inoue, T. Hashimoto +12
Characterizing the galaxy population in the early Universe holds the key to understanding the evolution of these objects and the role they played in cosmic reionization. However, t…
The impact of nebular emission on the broadband fluxes of high-redshift galaxies
E. Zackrisson, N. Bergvall, E. Leitet
A substantial fraction of the light emitted from young or star-forming galaxies at ultraviolet to near-infrared wavelengths comes from the ionized interstellar medium in the form o…
The Soft, Fluctuating UVB at as Traced by C IV, SiIV, and CII
K. Finlator, B. D. Oppenheimer, R. Davé +3
The sources that drove cosmological reionization left clues regarding their identity in the slope and inhomogeneity of the ultraviolet ionizing background (UVB): Bright quasars (QS…
Red Halos of Galaxies - Reservoirs of Baryonic Dark Matter?
E. Zackrisson, N. Bergvall, C. Flynn +3
Deep optical/near-IR surface photometry of galaxies outside the Local Group have revealed faint and very red halos around objects as diverse as disk galaxies and starbursting dwarf…
The dark matter halos of the bluest low surface brightness galaxies
E. Zackrisson, N. Bergvall, T. Marquart +1
We present BVI photometry and long-slit Halpha rotation curve data obtained with ESO VLT/FORS2 for six low surface brightness galaxies with extremely blue colours and very faint ce…
The Reionization of Carbon
K. Finlator, R. Thompson, S. Huang +3
Observations suggest that CII was more abundant than CIV in the intergalactic medium towards the end of the hydrogen reionization epoch. This transition provides a unique opportuni…
The stellar populations of the bluest low surface brightness galaxies
E. Zackrisson, N. Bergvall, G. Ostlin
Using optical/near-IR broadband photometry together with Halpha emission line data, we attempt to constrain the star formation histories, ages, total stellar masses and stellar mas…
The spectral evolution of the first galaxies. II. Spectral signatures of Lyman continuum leakage from galaxies in the reionization epoch
E. Zackrisson, A. K. Inoue, H. Jensen
The fraction of ionizing photons (fesc) that escape from z>6 galaxies is an important parameter when assessing the role of these objects in the reionization of the Universe, but th…
Revealing a Ring-like Cluster Complex in a Tidal Tail of the Starburst Galaxy NGC 2146
A. Adamo, L. J. Smith, J. S. Gallagher +9
We report the discovery of a ring-like cluster complex in the starburst galaxy NGC 2146. The Ruby Ring, so named due to its appearance, shows a clear ring-like distribution of star…
The observational signatures of high-redshift dark stars
E. Zackrisson
The annihilation of dark matter particles in the centers of minihalos may lead to the formation of so-called dark stars, which are cooler, larger, more massive and potentially more…
Terrestrial planets across space and time
E. Zackrisson, P. Calissendorff, J. Gonzalez +3
The study of cosmology, galaxy formation and exoplanets has now advanced to a stage where a cosmic inventory of terrestrial planets may be attempted. By coupling semi-analytic mode…
Prospects for CDM sub-halo detection using high angular resolution observations
T. Riehm, E. Zackrisson, O. Moeller +2
In the CDM scenario, dark matter halos are assembled hierarchically from smaller subunits. A long-standing problem with this picture is that the number of sub-halos predicted by CD…
The Red Halo Phenomenon
E. Zackrisson, N. Bergvall, G. Ostlin +2
Optical and near-IR observations of the halos of disk galaxies and blue compact galaxies have revealed a very red spectral energy distribution, which cannot easily be reconciled wi…
Unlocking the secrets of stellar haloes using combined star counts and surface photometry
E. Zackrisson, R. S. de Jong, G. Micheva
The stellar haloes of galaxies can currently be studied either through observations of resolved halo stars or through surface photometry. Curiously, the two methods appear to give…
Are the red halos of galaxies made of low-mass stars? Constraints from subdwarf star counts in the Milky Way halo
E. Zackrisson, C. Flynn
Surface photometry detections of red and exceedingly faint halos around galaxies have resurrected the old question of whether some non-negligible fraction of the missing baryons of…
Do blue compact galaxies have red halos?
E. Zackrisson, G. Micheva, N. Bergvall +1
Red halos are faint, extended and extremely red structures that have been reported around various types of galaxies since the mid-1990s. The colours of these halos are too red to b…
The Snapshot Hubble U-Band Cluster Survey (SHUCS). I. Survey Description and First Application to the Mixed Star Cluster Population of NGC 4041
I. S. Konstantopoulos, L. J. Smith, A. Adamo +9
We present the Snapshot Hubble U-band Cluster Survey (SHUCS), a project aimed at characterizing the star cluster populations of ten nearby galaxies (d<23 Mpc, half within 12 Mpc) t…
ANDES, the high resolution spectrograph for the ELT: science goals, project overview and future developments
A. Marconi, M. Abreu, V. Adibekyan +286
The first generation of ELT instruments includes an optical-infrared high-resolution spectrograph, indicated as ELT-HIRES and recently christened ANDES (ArmazoNes high Dispersion E…
The z = 9.625 Cosmic Gems Galaxy was a "Compact Blue Monster" Propelled by Massive Star Clusters
E. Vanzella, M. Messa, A. Adamo +36
The recent discovery of five massive stellar clusters at z=9.625 in the Cosmic Gems has raised the question about the formation mechanism of star clusters in the first half Gyr aft…
Constraining the mass of the GRB 030329 progenitor
G. Ostlin, E. Zackrisson, J. Sollerman +2
The long-duration gamma-ray burst (GRB) 030329, associated with supernova (SN) 2003dh, occurred inside a star-forming dwarf galaxy at redshift . The low redshift, and a r…
Constraining Dark Matter with the Long-Term Variability of Quasars
E. Zackrisson, N. Bergvall, P. Helbig
By comparing the results of numerical microlensing simulations to the observed long-term variability of quasars, strong upper limits on the cosmological density of compact objects…
Red halos and extragalactic background light
E. Zackrisson, G. Micheva
Deep surface photometry of disk galaxies at optical and near-IR wavelengths have revealed faint halos with colours much too red to be reconciled with the resolved stellar populatio…
How the extinction of extragalactic background light affects surface photometry of galaxies, groups and clusters
E. Zackrisson, G. Micheva, G. Ostlin
The faint regions of galaxies, groups and clusters hold important clues about how these objects formed, and surface photometry at optical and near-infrared wavelengths represents a…
Legacy ExtraGalactic UV Survey with The Hubble Space Telescope. Stellar cluster catalogues and first insights into cluster formation and evolution in NGC 628
A. Adamo, J. E. Ryon, M. Messa +53
We report the large effort which is producing comprehensive high-level young star cluster (YSC) catalogues for a significant fraction of galaxies observed with the Legacy ExtraGala…
A Comprehensive Comparative Test of Seven Widely-Used Spectral Synthesis Models Against Multi-Band Photometry of Young Massive Star Clusters
A. Wofford, S. Charlot, G. Bruzual +13
We test the predictions of spectral synthesis models based on seven different massive-star prescriptions against Legacy ExtraGalactic UV Survey (LEGUS) observations of eight young…