Fritze-von Alvensleben, Uta

[["dc.bibliographiccitation.firstpage","210"],["dc.bibliographiccitation.lastpage","211"],["dc.contributor.author","Anders, P."],["dc.contributor.author","van Alvensleben, U. F."],["dc.contributor.author","de Grijs, Richard"],["dc.date.accessioned","2018-11-07T10:53:12Z"],["dc.date.available","2018-11-07T10:53:12Z"],["dc.date.issued","2004"],["dc.description.abstract","Young clusters are observed to form in a variety of interacting galaxies and violent starbursts, a substantial number resembling the progenitors of the well-studied globular clusters in mass and size. By studying young clusters in merger remnants and peculiar galaxies, we can therefore learn about the violent star formation history of these galaxies. We present a new set of evolutionary synthesis models of our GALEV code specifically developed to include the gaseous emission of presently forming star clusters, and a new tool that allows to determine individual cluster metallicities, ages, extinction values and masses from a comparison of a large grid of model Spectral Energy Distributions (SEDs) with multi-color observations. First results for the newly-born clusters in NGC 1569 are presented."],["dc.identifier.isi","222682600050"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/49302"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Astronomical Soc Pacific"],["dc.publisher.place","San Francisco"],["dc.relation.conference","217th Symposium of the International-Astronomical-Union on Recycling Intergalactic and Interstellar Matter held at the 25th IAU General Assembly"],["dc.relation.eventend","2003-07-17"],["dc.relation.eventlocation","Sydney, Australia"],["dc.relation.eventstart","2003-07-14"],["dc.relation.isbn","1-58381-166-4"],["dc.relation.ispartof","Recycling intergalactic and interstellar matter; proceedings of the 217th Symposium of the International Astronomical Union held in Sydney, Australia 14 - 17 July 2003"],["dc.title","Young star clusters: Clues to galaxy formation and evolution"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","17"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Monthly Notices of the Royal Astronomical Society"],["dc.bibliographiccitation.lastpage","28"],["dc.bibliographiccitation.volume","347"],["dc.contributor.author","Anders, Peter"],["dc.contributor.author","de Grijs, Richard"],["dc.contributor.author","Fritze-von Alvensleben, Uta"],["dc.contributor.author","Bissantz, Nicolai"],["dc.date.accessioned","2018-11-07T10:52:55Z"],["dc.date.available","2018-11-07T10:52:55Z"],["dc.date.issued","2004"],["dc.description.abstract","We analyse multiwavelength Hubble Space Telescope (HST) observations of a large number of star clusters in the nearby (post-)starburst dwarf galaxy NGC 1569. Their spectral energy distributions (SEDs) cover at least the wavelength range from U to I in equivalent HST filters, in most cases supplemented by near-infrared data. Using our most up-to-date evolutionary synthesis models of the Gottingen GALEV code we determine ages, metallicities, extinction values and masses for each individual cluster robustly and independently. We confirm the youth of most of these objects. The majority were formed in a very intense starburst starting around 25 Myr ago. While there are two prominent 'super star clusters' present in this galaxy, with masses of (5-16) x 10(5) M., almost all remaining clusters are significantly less massive than an average Milky Way globular cluster, and are generally consistent with open cluster-type objects. We determine the cluster mass function from individual cluster masses derived by scaling the model SEDs of known mass to the observed cluster SEDs for each individual cluster. We find signs of a change in the cluster mass function as the burst proceeds, which we attribute to the special conditions of star cluster formation in this starburst dwarf galaxy environment."],["dc.identifier.doi","10.1111/j.1365-2966.2004.07171.x"],["dc.identifier.isi","000187257000004"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/49228"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Oxford Univ Press"],["dc.relation.issn","1365-2966"],["dc.relation.issn","0035-8711"],["dc.title","Star cluster formation and evolution in the dwarf starburst galaxy NGC 1569"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","867"],["dc.bibliographiccitation.journal","Highlights of Astronomy"],["dc.bibliographiccitation.lastpage","870"],["dc.bibliographiccitation.volume","13"],["dc.contributor.author","Anders, Peter"],["dc.contributor.author","Fritze-von Alvensleben, Uta"],["dc.contributor.author","de Grijs, Richard"],["dc.date.accessioned","2018-11-07T08:39:54Z"],["dc.date.available","2018-11-07T08:39:54Z"],["dc.date.issued","2005"],["dc.description.abstract","Star cluster formation is a major mode of star formation in the extreme conditions of interacting galaxies and violent star bursts. These newly-formed clusters are built from recycled gas, pre-enriched to various levels within the interacting galaxies. Hence, star clusters of different ages represent a fossil record of the chemical enrichment history of their host galaxy, as well as of the host galaxy's violent star formation history. We present a new set of evolutionary synthesis models of our GALEV code, specifically developed to include the gaseous emission of presently forming star clusters, and a new tool to analyze multi-color observations with our models. First results for newly-born clusters in the dwarf star-burst galaxy NGC 1569 are presented."],["dc.identifier.isi","240768700242"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/19113"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Astronomical Soc Pacific"],["dc.publisher.place","San francisco"],["dc.relation.conference","25th General Assembly of the International-Astronomical-Union"],["dc.relation.eventlocation","Sydney, AUSTRALIA"],["dc.relation.isbn","1-58381-189-3"],["dc.relation.issn","0074-1809"],["dc.title","Young star clusters: Metallicity tracers in external galaxies"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","937"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Astrophysics and Space Science"],["dc.bibliographiccitation.lastpage","940"],["dc.bibliographiccitation.volume","284"],["dc.contributor.author","Anders, Peter"],["dc.contributor.author","Fritze-von Alvensleben, Uta"],["dc.contributor.author","de Grijs, Richard"],["dc.date.accessioned","2018-11-07T10:42:03Z"],["dc.date.available","2018-11-07T10:42:03Z"],["dc.date.issued","2003"],["dc.description.abstract","The observational properties of globular cluster systems (GCSs) are vital tools to investigate the violent star formation histories of their host galaxies. This violence is thought to have been triggered by galaxy interactions or mergers. The most basic properties of a GCS are its luminosity function (number of clusters per luminosity bin) and color distributions. A large number of observed GCSs show bimodal color distributions, which can be translated into a bimodality in either metallicity and/or age. An additional uncertainty comes into play when one considers extinction. These effects can be disentangled either by obtaining spectroscopic data for the clusters or by imaging observations in at least four passbands. This allows us then to discriminate between various formation scenarios of GCSs, e. g. the merger scenario by Ashman and Zepf, and the multi-phase collapse model by Forbes et al. Young and metal-rich star cluster populations are seen to form in interacting and merging galaxies. We analyse multiwavelength broad-band observations of these young cluster systems provided by the ASTROVIRTEL project."],["dc.identifier.doi","10.1023/A:1024068211049"],["dc.identifier.isi","000183320500130"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/46693"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Kluwer Academic Publ"],["dc.publisher.place","Dordrecht"],["dc.relation.conference","Conference on the Appropriate Modellings of Galaxy Evolution from their Cosmological Formation to their Presently Observable Structures"],["dc.relation.eventlocation","KIEL, GERMANY"],["dc.relation.issn","0004-640X"],["dc.title","Evolutionary synthesis modelling of young star clusters in merging galaxies"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","91"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Monthly Notices of the Royal Astronomical Society"],["dc.bibliographiccitation.lastpage","106"],["dc.bibliographiccitation.volume","377"],["dc.contributor.author","Anders, Peter"],["dc.contributor.author","Bissantz, Nicolai"],["dc.contributor.author","Boysen, Leif"],["dc.contributor.author","de Grijs, Richard"],["dc.contributor.author","Fritze-von Alvensleben, Uta"],["dc.date.accessioned","2018-11-07T11:02:55Z"],["dc.date.available","2018-11-07T11:02:55Z"],["dc.date.issued","2007"],["dc.description.abstract","The luminosity functions (LFs) of star cluster (SC) systems (i.e. the number of clusters per luminosity interval) are vital diagnostics to probe the conditions of SC formation. Early studies have revealed a clear dichotomy between old globular clusters and young clusters, with the former characterized by Gaussian-shaped LFs, and the latter following a power law. Recently, this view was challenged by studies of galaxy merger remnants and post-starburst galaxies. In this paper, we re-evaluate the young (less than or similar to few hundreds of Myrs, with the majority less than or similar to few tens of Myrs) SC system in the ongoing spiral-spiral major merger system NGC 4038/39, the 'Antennae' galaxies. The Antennae galaxies represent a very active and complex star-forming environment, which hampers cluster selection and photometry as well as the determination of observational completeness fractions. A main issue of concern is the large number of bright young stars contained in most earlier studies, which we carefully exclude from our cluster sample by accurately determining the source sizes. The resulting LFs are fitted both with Gaussian and with power-law distributions, taking into account both the observational completeness fractions and the photometric errors, and compared using a likelihood-ratio test. The likelihood-ratio results are rigidly evaluated using Monte Carlo simulations. We perform a number of additional tests, for example, with subsets of the total sample, all confirming our main result: that a Gaussian distribution fits the observed LFs of clusters in this preferentially very young cluster system significantly better than a power-law distribution, at a (statistical) error probability of less than 0.5 per cent."],["dc.identifier.doi","10.1111/j.1365-2966.2007.11629.x"],["dc.identifier.isi","000246797900025"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/51498"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Oxford Univ Press"],["dc.relation.issn","1365-2966"],["dc.relation.issn","0035-8711"],["dc.title","The young star cluster system in the Antennae: evidence for a turnover in the luminosity function"],["dc.type","review"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","366"],["dc.bibliographiccitation.journal","Highlights of Astronomy"],["dc.bibliographiccitation.lastpage","368"],["dc.bibliographiccitation.volume","13"],["dc.contributor.author","Anders, Peter"],["dc.contributor.author","v. Alvensleben, Uta Fritze"],["dc.contributor.author","de Grijs, Richard"],["dc.date.accessioned","2018-11-07T08:39:52Z"],["dc.date.available","2018-11-07T08:39:52Z"],["dc.date.issued","2005"],["dc.description.abstract","Star cluster formation is a major mode of star formation in the extreme conditions of interacting galaxies and violent starbursts. Young clusters are observed to form in a variety of such galaxies, a substantial number resembling the progenitors of globular clusters in mass and size, but with significantly enhanced metallicity. From studies of the metal-poor and metal-rich star cluster populations of galaxies, we can therefore learn about the violent star formation history of these galaxies, and eventually about galaxy formation and evolution. We present a new set of evolutionary synthesis models of our GALEV code, with special emphasis on the gaseous emission of presently forming star clusters, and a new tool to compare extensive model grids with multi-color broad-band observations to determine individual cluster masses, metallicities, ages and extinction values independently. First results for young star clusters in the dwarf starburst galaxy NGC 1569 are presented. The mass distributions determined for the young clusters give valuable input to dynamical star cluster system evolution models, regarding survival and destruction of clusters. We plan to investigate an age sequence of galaxy mergers to see dynamical destruction effects in process."],["dc.identifier.isi","240768700105"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/19102"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Astronomical Soc Pacific"],["dc.publisher.place","San francisco"],["dc.relation.conference","25th General Assembly of the International-Astronomical-Union"],["dc.relation.eventlocation","Sydney, AUSTRALIA"],["dc.relation.isbn","1-58381-189-3"],["dc.relation.issn","0074-1809"],["dc.title","Young star clusters: Progenitors of globular clusters!?"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","259"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Monthly Notices of the Royal Astronomical Society"],["dc.bibliographiccitation.lastpage","273"],["dc.bibliographiccitation.volume","342"],["dc.contributor.author","de Grijs, Richard"],["dc.contributor.author","Fritze-von Alvensleben, Uta"],["dc.contributor.author","Anders, Peter"],["dc.contributor.author","Gallagher, J. S."],["dc.contributor.author","Bastian, N."],["dc.contributor.author","Taylor, V. A."],["dc.contributor.author","Windhorst, R. A."],["dc.date.accessioned","2018-11-07T10:38:17Z"],["dc.date.available","2018-11-07T10:38:17Z"],["dc.date.issued","2003"],["dc.description.abstract","The large majority of extragalactic star cluster studies performed to date have essentially used two- or three-passband aperture photometry, combined with theoretical stellar population synthesis models, to obtain age, mass and extinction estimates, and sometimes also metallicities. The accuracy to which this can be performed depends on the choice of (broad-band) passband combination and, crucially, also on the actual wavelengths and the wavelength range covered by the observations. Understanding the inherent systematic uncertainties (the main aim of this paper) is of the utmost importance for a well-balanced interpretation of the properties of extragalactic star cluster systems. We simultaneously obtain ages, metallicities and extinction values for similar to300 clusters in the nearby starburst galaxy NGC 3310, based on archival Hubble Space Telescope observations from the ultraviolet (UV) to the near-infrared (NIR). We show that for ages 6 less than or similar to log(age yr(-1)) less than or similar to 9, and if one can only obtain partial coverage of the spectral energy distribution (SED), an optical passband combination of at least four filters including both blue and red passbands results in the most representative age distribution, as compared with the better constrained ages obtained from the full UV-NIR SED coverage. We find that while blue-selected passband combinations lead to age distributions that are slightly biased towards lower ages due to the well-known age-metallicity degeneracy, red-dominated passband combinations should be avoided. NGC 3310 underwent a (possibly extended) global burst of cluster formation similar to3 x 10(7) yr ago. This coincides closely with the last tidal interaction or merger with a low-metallicity galaxy that probably induced the formation of the large fraction of clusters with (significantly) subsolar metallicities. The logarithmic slope of the V-band cluster luminosity function, for clusters in the range 17.7 less than or similar to F606W less than or similar to 20.2 mag, is alpha(F606W) similar or equal to -1.8 +/- 0.4. The observed cluster system has a median mass of (log(m/M-.)) similar or equal to 5.25 +/- 0.1, obtained from scaling the appropriate model SEDs for known masses to the observed cluster SEDs."],["dc.identifier.doi","10.1046/j.1365-8711.2003.06536.x"],["dc.identifier.isi","000183549500028"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/45777"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Oxford Univ Press"],["dc.relation.issn","1365-2966"],["dc.relation.issn","0035-8711"],["dc.title","Star cluster formation and evolution in nearby starburst galaxies - I. Systematic uncertainties"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","874"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Monthly Notices of the Royal Astronomical Society"],["dc.bibliographiccitation.lastpage","894"],["dc.bibliographiccitation.volume","359"],["dc.contributor.author","de Grijs, Richard"],["dc.contributor.author","Anders, Peter"],["dc.contributor.author","Lamers, HJGLM"],["dc.contributor.author","Bastian, N."],["dc.contributor.author","Fritze-Von Alvensleben, U."],["dc.contributor.author","Parmentier, G."],["dc.contributor.author","Sharina, M. E."],["dc.contributor.author","Yi, S."],["dc.date.accessioned","2018-11-07T11:00:11Z"],["dc.date.available","2018-11-07T11:00:11Z"],["dc.date.issued","2005"],["dc.description.abstract","High-resolution Hubble Space Telescope (HST) imaging observations of star cluster systems provide a very interesting and useful alternative to spectroscopic studies for stellar population analyses with 8-m class telescopes. Here, we assess the systematic uncertainties in ( young) cluster age, mass and ( to a lesser extent) extinction and metallicity determinations, based on broad-band imaging observations with the HST. Our aim here is to intercompare the results obtained using a variety of commonly used modelling techniques, specifically with respect to our own extensively tested multidimensional approach. Any significant differences among the resulting parameters are due to the details of the various, independently developed, modelling techniques used, rather than to the stellar population models themselves. Despite the model uncertainties and the selection effects inherent to most methods used, we find that the peaks in the relative age and mass distributions of a given young (less than or similar to 10(9) yr) cluster system can be derived relatively robustly and consistently, to accuracies of sigma(t) equivalent to Delta < log(age/yr)> <= 0.35 and sigma(M) = equivalent to Delta log(M-cl/M-circle dot)> <= 0.14, respectively, assuming Gaussian distributions in cluster ages and masses for reasons of simplicity. The peaks in the relative mass distributions can be obtained with a higher degree of confidence than those in the relative age distributions, as exemplified by the smaller spread among the peak values of the mass distributions derived. This implies that mass determinations are mostly insensitive to the approach adopted. We reiterate that as extensive a wavelength coverage as possible is required to obtain robust and internally consistent age and mass estimates for the individual objects, with reasonable uncertainties. Finally, we conclude that the actual filter systems used for the observations should be used for constructing model colours, instead of using conversion equations, to achieve more accurate derivations of ages and masses."],["dc.identifier.doi","10.1111/j.1365-2966.2005.08914.x"],["dc.identifier.isi","000229015700008"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/50871"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Oxford Univ Press"],["dc.relation.issn","1365-2966"],["dc.relation.issn","0035-8711"],["dc.title","Systematic uncertainties in the analysis of star cluster parameters based on broad-band imaging observations"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.journal","Highlights of Astronomy"],["dc.bibliographiccitation.volume","13"],["dc.contributor.author","Anders, Peter"],["dc.contributor.author","v. Alvensleben, Uta Fritze-"],["dc.contributor.author","de Grijs, Richard"],["dc.date.accessioned","2018-11-07T08:39:49Z"],["dc.date.available","2018-11-07T08:39:49Z"],["dc.date.issued","2005"],["dc.description.abstract","We present a new set of evolutionary synthesis models of our GALEV code, specifically developed to include the gaseous emission of presently forming star clusters, in combination with an advanced tool to compare large model grids with multi-color broad-band observations of YSC systems. Tests and first applications are presented."],["dc.format.extent","195"],["dc.identifier.isi","000240768700068"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/19091"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Astronomical Soc Pacific"],["dc.publisher.place","San francisco"],["dc.relation.conference","25th General Assembly of the International-Astronomical-Union"],["dc.relation.eventlocation","Sydney, AUSTRALIA"],["dc.relation.isbn","1-58381-189-3"],["dc.relation.issn","0074-1809"],["dc.title","Multi-color observations of young star clusters"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","187"],["dc.bibliographiccitation.journal","Highlights of Astronomy"],["dc.bibliographiccitation.lastpage","188"],["dc.contributor.author","v. Alvensleben, Uta Fritze-"],["dc.contributor.author","Anders, Peter"],["dc.contributor.author","de Grijs, Richard"],["dc.date.accessioned","2018-11-07T08:39:47Z"],["dc.date.available","2018-11-07T08:39:47Z"],["dc.date.issued","2005"],["dc.description.abstract","Evolutionary synthesis models for star clusters of various metallicities, including gaseous emission during the lifetime of the ionizing stars, are used to model star cluster systems comprising two populations: an old metal-poor globular cluster (GC) population similar to that of the Milky Way halo, and a second GC population of arbitrary metallicity. We investigate the time evolution of color distributions and luminosity functions for the two GC populations and compare with observations of E/S0 galaxies. We show that multi-passband data for GC populations give clues to the relative ages and metallicities of the two subpopulations, and help constrain formation scenarios for their parent galaxies."],["dc.identifier.isi","000240768700064"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/19080"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Astronomical Soc Pacific"],["dc.publisher.place","San francisco"],["dc.relation.conference","25th General Assembly of the International-Astronomical-Union"],["dc.relation.eventlocation","Sydney, AUSTRALIA"],["dc.relation.isbn","1-58381-189-3"],["dc.relation.issn","0074-1809"],["dc.title","From young to old: Spectral models for star cluster systems"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]