Schuh, Sonja

[["dc.bibliographiccitation.firstpage","457"],["dc.bibliographiccitation.issue","3-4"],["dc.bibliographiccitation.journal","Astrophysics and Space Science"],["dc.bibliographiccitation.lastpage","464"],["dc.bibliographiccitation.volume","291"],["dc.contributor.author","O'Toole, S. J."],["dc.contributor.author","Falter, S."],["dc.contributor.author","Heber, Ulrich"],["dc.contributor.author","Jeffery, C. S."],["dc.contributor.author","Dreizler, Stefan"],["dc.contributor.author","Schuh, S. L."],["dc.date.accessioned","2018-11-07T10:52:04Z"],["dc.date.available","2018-11-07T10:52:04Z"],["dc.date.issued","2004"],["dc.description.abstract","We present the first results from the MultiSite Spectroscopic Telescope (MSST) observations of the sdBV star PG 1605+072. Pulsating sdB stars (also known as EC 14026 stars) offer the chance to gain new insights into the formation and evolution of extreme Horizontal Branch stars using the tools of asteroseismology. PG1605+072 is an outstanding object in its class, with the richest frequency spectrum, the longest periods, and the largest variations. The MSST campaign took place in May/June 2002 immediately following the Whole Earth Telescope Xcov22 run, which observed PG 1605+072 as an alternate target. We will first give an overview of the project and its feasibility, after which we will present the massive data set, made up of 399 h of photometry and 151 h of spectroscopy. The overall aims of the project are to examine light/velocity amplitude ratios and phase differences, changes in equivalent width/line index, and lambda-dependence of photometric amplitudes, and to use these properties for mode identification."],["dc.identifier.doi","10.1023/B:ASTR.0000044360.79737.38"],["dc.identifier.isi","000224389400041"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/49036"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Kluwer Academic Publ"],["dc.publisher.place","Dordrecht"],["dc.relation.conference","Meeting on sdB Stars"],["dc.relation.eventlocation","Keele Univ, Staffordshire, ENGLAND"],["dc.relation.issn","0004-640X"],["dc.title","MSST observations of the pulsating sdB star PG 1605+072"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","L31"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.lastpage","L34"],["dc.bibliographiccitation.volume","445"],["dc.contributor.author","Schuh, Sonja"],["dc.contributor.author","Huber, Johannes"],["dc.contributor.author","Dreizler, Stefan"],["dc.contributor.author","Heber, Ulrich"],["dc.contributor.author","O'Toole, S. J."],["dc.contributor.author","Green, Elizabeth M."],["dc.contributor.author","Fontaine, Gilles"],["dc.date.accessioned","2018-11-07T10:30:18Z"],["dc.date.available","2018-11-07T10:30:18Z"],["dc.date.issued","2006"],["dc.description.abstract","Context. The hot subdwarf B star HS 0702 0702+6043 is known as a large-amplitude, short-period p-mode pulsator of the EC 14026 type. Its atmospheric parameters place it at the common boundary between the empirical instability regions of the EC 14026 variables and the typically C cooler long-period g-mode pulsators of the PG1716 kind. Aims. We analyse and interpret the photometric var variability iability of HS 0702 0702+ 6043 in order to explore its asteroseismological potential. Methods. We report on rapid wide band CCD photometric observations to follow up on and confirm the serendipitous discovery of multiperiodic long- period luminosity variations with typical time scales of similar to 1 h in HS 0702 0702+6043, in addition to the two previously known pulsations at 363 s and 383 s. In particular, we isolate a relatively low-amplitude (similar to 4 mmag), long-period (3538 +/- 130 s) light variation. Results. We argue that the most likely origin for this luminosity variation is the presence of an excited g-mode pulsation. If confirmed, HS 0702 0702+6043 would constitute a rare addition to the very select class of pulsating stars showing sim lect simultaneously parts of their pressure and ultaneously gravity mode pulsation spectra. The asteroseismological potential of such stars is immense, and HS 0702 0702+6043 thus becomes a target of choice for future investigations. While our discovery appears consistent with the location of HS 0702 0702+6043 at the common boundary between the two families of pulsating sdB stars, it does challenge theory's current description of stability and driving mechanisms in pulsating B subdwarfs."],["dc.identifier.doi","10.1051/0004-6361:200500210"],["dc.identifier.fs","45041"],["dc.identifier.isi","000234404500003"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/7680"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/43835"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Edp Sciences S A"],["dc.relation.issn","1432-0746"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","HS 0702+6043: a star showing both short-period p-mode and long-period g-mode oscillations"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","321"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","BALTIC ASTRONOMY"],["dc.bibliographiccitation.lastpage","325"],["dc.bibliographiccitation.volume","15"],["dc.contributor.author","Jeffery, C. S."],["dc.contributor.author","Heber, Ulrich"],["dc.contributor.author","Dreizler, Stefan"],["dc.contributor.author","O'Toole, S. J."],["dc.contributor.author","Schuh, S. L."],["dc.contributor.author","Woolf, Vincent M."],["dc.contributor.author","Falter, S."],["dc.contributor.author","Nitta, A."],["dc.contributor.author","Kleinman, S."],["dc.contributor.author","Krzesinski, J."],["dc.contributor.author","Billeres, M."],["dc.date.accessioned","2018-11-07T10:30:35Z"],["dc.date.available","2018-11-07T10:30:35Z"],["dc.date.issued","2006"],["dc.description.abstract","The MultiSite Spectroscopic Telescope (MSST) campaign aimed to provide a detailed view of the short-period pulsating subdwarf B star PC 1605+ 072. We present results from the part of the campaign undertaken on 4 m telescopes in 2002 May and June."],["dc.identifier.isi","000237216400026"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/43901"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Inst Theoretical Physics Astronomy"],["dc.publisher.place","Moletai"],["dc.relation.conference","2nd Meeting on Hot Subdwarf Stars and Related Objects"],["dc.relation.eventlocation","Santa Cruz de la Palma, SPAIN"],["dc.relation.issn","1392-0049"],["dc.title","The MSST campaign: 4 m spectroscopy of PG 1605+072"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","667"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.lastpage","674"],["dc.bibliographiccitation.volume","440"],["dc.contributor.author","O'Toole, S. J."],["dc.contributor.author","Heber, Ulrich"],["dc.contributor.author","Jeffery, C. S."],["dc.contributor.author","Dreizler, Stefan"],["dc.contributor.author","Schuh, S. L."],["dc.contributor.author","Woolf, Vincent M."],["dc.contributor.author","Falter, S."],["dc.contributor.author","Green, Elizabeth M."],["dc.contributor.author","For, B. Q."],["dc.contributor.author","Hyde, E. A."],["dc.contributor.author","Kjeldsen, Hans"],["dc.contributor.author","Mauch, T."],["dc.contributor.author","White, B. A."],["dc.date.accessioned","2018-11-07T10:55:55Z"],["dc.date.available","2018-11-07T10:55:55Z"],["dc.date.issued","2005"],["dc.description.abstract","We present results and analysis for the 2m spectroscopic part of the MultiSite Spectroscopic Telescope (MSST) campaign undertaken in May/June 2002. The goal of the project was to observe the pulsating subdwarf B star PG1605+072 simultaneously in velocity and photometry and to resolve as many of the > 50 known modes as possible, which will allow a detailed asteroseismological analysis. We have obtained over 150 h of spectroscopy, leading to an unprecedented noise level of only 207 m s(-1). We report here the detection of 20 frequencies in velocity, with two more likely just below our detection threshold. In particular, we detect 6 linear combinations, making PG1605+072 only the second star known to show such frequencies in velocity. We investigate the phases of these combinations and their parent modes and find relationships between them that cannot be easily understood based on current theory. These observations, when combined with our simultaneous photometry, should allow asteroseismology of this most complicated of sdB pulsators."],["dc.identifier.doi","10.1051/0004-6361:20053352"],["dc.identifier.fs","38258"],["dc.identifier.isi","000231547400033"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/9866"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/49894"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","0004-6361"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","The MultiSite Spectroscopic Telescope campaign: 2 m spectroscopy of the V361 Hya variable PG1605+072"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","138"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","The Astrophysical Journal"],["dc.bibliographiccitation.lastpage","143"],["dc.bibliographiccitation.volume","711"],["dc.contributor.author","Irrgang, Andreas"],["dc.contributor.author","Przybilla, Norbert"],["dc.contributor.author","Heber, Ulrich"],["dc.contributor.author","Nieva, M. Fernanda"],["dc.contributor.author","Schuh, Sonja"],["dc.date.accessioned","2018-11-07T08:45:11Z"],["dc.date.available","2018-11-07T08:45:11Z"],["dc.date.issued","2010"],["dc.description.abstract","Young, massive stars in the Galactic halo are widely supposed to be the result of an ejection event from the Galactic disk forcing some stars to leave their place of birth as so-called runaway stars. Here, we present a detailed spectroscopic and kinematic analysis of the runaway B star HIP 60350 to determine which runaway scenario-a supernova explosion disrupting a binary system or dynamical interaction in star clusters-may be responsible for HIP 60350's peculiar orbit. Based on a non-local thermodynamic equilibrium approach, a high-resolution optical echelle spectrum was examined to revise spectroscopic quantities and for the first time to perform a differential chemical abundance analysis with respect to the B-type star 18 Peg. The results together with proper motions from the Hipparcos Catalog further allowed the three-dimensional kinematics of the star to be studied numerically. The abundances derived for HIP 60350 are consistent with a slightly supersolar metallicity agreeing with the kinematically predicted place of birth similar to 6 kpc away from the Galactic center. However, they do not exclude the possibility of an alpha-enhanced abundance pattern expected in the case of the supernova scenario. Its outstanding high Galactic rest-frame velocity of 530 +/- 35 km s(-1) is a consequence of ejection in the direction of Galactic rotation and slightly exceeds the local Galactic escape velocity in a standard Galactic potential. Hence, IIIP 60350 may be unbound to the Galaxy."],["dc.identifier.doi","10.1088/0004-637X/711/1/138"],["dc.identifier.isi","000274417500012"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/20375"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Iop Publishing Ltd"],["dc.relation.issn","0004-637X"],["dc.title","THE NATURE OF THE HYPER-RUNAWAY CANDIDATE HIP 60350"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","219"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.lastpage","228"],["dc.bibliographiccitation.volume","473"],["dc.contributor.author","Tillich, A."],["dc.contributor.author","Heber, Ulrich"],["dc.contributor.author","O'Toole, S. J."],["dc.contributor.author","Ostensen, Roy H."],["dc.contributor.author","Schuh, Sonja"],["dc.date.accessioned","2018-11-07T10:57:55Z"],["dc.date.available","2018-11-07T10:57:55Z"],["dc.date.issued","2007"],["dc.description.abstract","Context. Stellar oscillations are an important tool to probe the interior of a star. Subdwarf B stars are core helium burning objects, but their formation is poorly understood as neither single star nor binary evolution can fully explain their observed properties. Since 1997, an increasing number of sdB stars has been found to pulsate forming two classes of stars, the V361 Hya and V1093 Her stars. Aims. We focus on the bright V 361 Hya star PG 1605+ 072 to characterise its frequency spectrum. While most previous studies relied on light variations, we have measured radial velocity variations for as many as 20 modes. In this paper, we aim at characterising the modes from atmospheric parameter and radial velocity variations. Methods. Time resolved spectroscopy (approximate to 9000 spectra) has been carried out to detect line profile variations from which variations of the effective temperature and gravity are extracted by means of a quantitative spectral analysis. Results. We measured variations of effective temperatures and gravities for eight modes with semi- amplitudes ranging from Delta T-eff = 880 K to as small as 88 K, and. log g of 0.08 dex to as low as 0.008 dex. Gravity and temperature vary almost in phase, whereas phase lags are found between temperature and radial velocity. Conclusions. This profound analysis of a unique data set serves as a sound basis for the next step towards an identification of pulsation modes. As rotation may play an important role, the modelling of pulsation modes is challenging but feasible."],["dc.identifier.doi","10.1051/0004-6361:20077949"],["dc.identifier.isi","000249957800024"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/9075"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/50363"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Edp Sciences S A"],["dc.relation.issn","0004-6361"],["dc.relation.orgunit","Fakultät für Physik"],["dc.rights","Goescholar"],["dc.rights.access","openAccess"],["dc.rights.uri","https://goedoc.uni-goettingen.de/licenses"],["dc.title","The multi-site spectroscopic telescope campaign - II. effective temperature and gravity variations in the multi-periodic pulsating subdwarf B star PG 1605+072"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","submitted_version"],["dspace.entity.type","Publication"]]