Nielsen, Martin Bo

[["dc.bibliographiccitation.artnumber","A79"],["dc.bibliographiccitation.journal","Astronomy & Astrophysics"],["dc.bibliographiccitation.volume","586"],["dc.contributor.author","Schunker, H."],["dc.contributor.author","Schou, J."],["dc.contributor.author","Ball, Warrick H."],["dc.contributor.author","Nielsen, M. B."],["dc.contributor.author","Gizon, Laurent"],["dc.date.accessioned","2017-09-07T11:48:42Z"],["dc.date.available","2017-09-07T11:48:42Z"],["dc.date.issued","2015"],["dc.description.abstract","Context. Radial differential rotation is an important parameter for stellar dynamo theory and for understanding angular momentum transport.Aims. We investigate the potential of using a large number of similar stars simultaneously to constrain their average radial differential rotation gradient: we call this “ensemble fitting”.Methods. We use a range of stellar models along the main sequence, each with a synthetic rotation profile. The rotation profiles are step functions with a step of ΔΩ = −0.35 μHz, which is located at the base of the convection zone. These models are used to compute the rotational splittings of the p modes and to model their uncertainties. We then fit an ensemble of stars to infer the average ΔΩ.Results. All the uncertainties on the inferred ΔΩ for individual stars are of the order 1 μHz. Using 15 stellar models in an ensemble fit, we show that the uncertainty on the average ΔΩ is reduced to less than the input ΔΩ, which allows us to constrain the sign of the radial differential rotation. We show that a solar-like ΔΩ ≈ 30 nHz can be constrained by an ensemble fit of thousands of main-sequence stars. Observing the number of stars required to successfully exploit the ensemble fitting method will be possible with future asteroseismology missions, such as PLATO. We demonstrate the potential of ensemble fitting by showing that any systematic differences in the average ΔΩ between F, G, and K-type stars larger than 100 nHz could be detected."],["dc.identifier.doi","10.1051/0004-6361/201527485"],["dc.identifier.gro","3147043"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/13440"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/4775"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","public"],["dc.notes.submitter","chake"],["dc.relation.issn","0004-6361"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","Asteroseismic inversions for radial differential rotation of Sun-like stars: ensemble fits"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","119"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","The Astrophysical Journal"],["dc.bibliographiccitation.volume","857"],["dc.contributor.author","Benomar, O."],["dc.contributor.author","Goupil, Mjo."],["dc.contributor.author","Belkacem, K."],["dc.contributor.author","Appourchaux, T."],["dc.contributor.author","Nielsen, M. B."],["dc.contributor.author","Bazot, M."],["dc.contributor.author","Gizon, Laurent"],["dc.contributor.author","Hanasoge, S."],["dc.contributor.author","Sreenivasan, K. R."],["dc.contributor.author","Marchand, B."],["dc.date.accessioned","2020-12-10T18:47:34Z"],["dc.date.available","2020-12-10T18:47:34Z"],["dc.date.issued","2018"],["dc.identifier.doi","10.3847/1538-4357/aab9b7"],["dc.identifier.eissn","1538-4357"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/78809"],["dc.notes.intern","DOI Import GROB-354"],["dc.title","Asymmetry of Line Profiles of Stellar Oscillations Measured by Kepler for Ensembles of Solar-like Oscillators: Impact on Mode Frequencies and Dependence on Effective Temperature"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","L9"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.volume","619"],["dc.contributor.author","Bazot, M."],["dc.contributor.author","Nielsen, M. B."],["dc.contributor.author","Mary, D."],["dc.contributor.author","Christensen-Dalsgaard, J."],["dc.contributor.author","Benomar, O."],["dc.contributor.author","Petit, P."],["dc.contributor.author","Gizon, Laurent"],["dc.contributor.author","Sreenivasan, K. R."],["dc.contributor.author","White, T. R."],["dc.date.accessioned","2020-12-10T18:11:44Z"],["dc.date.available","2020-12-10T18:11:44Z"],["dc.date.issued","2018"],["dc.identifier.doi","10.1051/0004-6361/201834251"],["dc.identifier.eissn","1432-0746"],["dc.identifier.issn","0004-6361"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/74126"],["dc.notes.intern","DOI Import GROB-354"],["dc.title","Butterfly diagram of a Sun-like star observed using asteroseismology"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","A125"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.volume","623"],["dc.contributor.author","Bazot, M."],["dc.contributor.author","Benomar, O."],["dc.contributor.author","Christensen-Dalsgaard, J."],["dc.contributor.author","Gizon, Laurent"],["dc.contributor.author","Hanasoge, S."],["dc.contributor.author","Nielsen, M."],["dc.contributor.author","Petit, P."],["dc.contributor.author","Sreenivasan, K. R."],["dc.date.accessioned","2020-12-10T18:11:45Z"],["dc.date.available","2020-12-10T18:11:45Z"],["dc.date.issued","2019"],["dc.identifier.doi","10.1051/0004-6361/201834594"],["dc.identifier.eissn","1432-0746"],["dc.identifier.issn","0004-6361"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/74132"],["dc.notes.intern","DOI Import GROB-354"],["dc.title","Latitudinal differential rotation in the solar analogues 16 Cygni A and B"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","A82"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.volume","601"],["dc.contributor.author","White, Timothy R."],["dc.contributor.author","Benomar, O."],["dc.contributor.author","Aguirre, Victor Silva"],["dc.contributor.author","Ball, Warrick H."],["dc.contributor.author","Bedding, Timothy R."],["dc.contributor.author","Chaplin, W. J."],["dc.contributor.author","Christensen-Dalsgaard, Joergen"],["dc.contributor.author","Garcia, R. A."],["dc.contributor.author","Gizon, Laurent"],["dc.contributor.author","Stello, Dennis"],["dc.contributor.author","Aigrain, S."],["dc.contributor.author","Antia, H. M."],["dc.contributor.author","Appourchaux, T."],["dc.contributor.author","Bazot, M."],["dc.contributor.author","Campante, Tiago L."],["dc.contributor.author","Creevey, O. L."],["dc.contributor.author","Davies, G. R."],["dc.contributor.author","Elsworth, Yvonne P."],["dc.contributor.author","Gaulme, P."],["dc.contributor.author","Handberg, Rasmus"],["dc.contributor.author","Hekker, Saskia"],["dc.contributor.author","Houdek, Gunter"],["dc.contributor.author","Howe, R."],["dc.contributor.author","Huber, D."],["dc.contributor.author","Karoff, Christoffer"],["dc.contributor.author","Marques, J. P."],["dc.contributor.author","Mathur, S."],["dc.contributor.author","McQuillan, A."],["dc.contributor.author","Metcalfe, T. S."],["dc.contributor.author","Mosser, B."],["dc.contributor.author","Nielsen, M. B."],["dc.contributor.author","Regulo, C."],["dc.contributor.author","Salabert, D."],["dc.contributor.author","Stahn, Thorsten"],["dc.date.accessioned","2018-11-07T10:24:05Z"],["dc.date.available","2018-11-07T10:24:05Z"],["dc.date.issued","2017"],["dc.description.abstract","Binary star systems are important for understanding stellar structure and evolution, and are especially useful when oscillations can be detected and analysed with asteroseismology. However, only four systems are known in which solar-like oscillations are detected in both components. Here, we analyse the fifth such system, HD 176465, which was observed by Kepler. We carefully analysed the system's power spectrum to measure individual mode frequencies, adapting our methods where necessary to accommodate the fact that both stars oscillate in a similar frequency range. We also modelled the two stars independently by fitting stellar models to the frequencies and complementary parameters. We are able to cleanly separate the oscillation modes in both systems. The stellar models produce compatible ages and initial compositions for the stars, as is expected from their common and contemporaneous origin. Combining the individual ages, the system is about 3.0 +/- 0.5 Gyr old. The two components of HD 176465 are young physically-similar oscillating solar analogues, the first such system to be found, and provide important constraints for stellar evolution and asteroseismology."],["dc.identifier.doi","10.1051/0004-6361/201628706"],["dc.identifier.isi","000402313500082"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/15004"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/42591"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","PUB_WoS_Import"],["dc.publisher","Edp Sciences S A"],["dc.relation","info:eu-repo/grantAgreement/EC/FP7/338251/EU//STELLARAGES"],["dc.relation.issn","1432-0746"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","Kepler observations of the asteroseismic binary HD 176465"],["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.artnumber","L12"],["dc.bibliographiccitation.journal","Astronomy & Astrophysics"],["dc.bibliographiccitation.volume","568"],["dc.contributor.author","Nielsen, M. B."],["dc.contributor.author","Gizon, Laurent"],["dc.contributor.author","Schunker, H."],["dc.contributor.author","Schou, J."],["dc.date.accessioned","2017-09-07T11:48:42Z"],["dc.date.available","2017-09-07T11:48:42Z"],["dc.date.issued","2014"],["dc.identifier.doi","10.1051/0004-6361/201424525"],["dc.identifier.fs","609660"],["dc.identifier.gro","3147028"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/10930"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/4765"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","public"],["dc.notes.submitter","chake"],["dc.publisher","EDP Sciences"],["dc.relation.issn","0004-6361"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","Rotational splitting as a function of mode frequency for six Sun-like stars"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","L10"],["dc.bibliographiccitation.journal","Astronomy & Astrophysics"],["dc.bibliographiccitation.volume","557"],["dc.contributor.author","Nielsen, M. B."],["dc.contributor.author","Gizon, Laurent"],["dc.contributor.author","Schunker, H."],["dc.contributor.author","Karoff, C."],["dc.date.accessioned","2017-09-07T11:48:42Z"],["dc.date.available","2017-09-07T11:48:42Z"],["dc.date.issued","2013"],["dc.description.abstract","We aim to measure the starspot rotation periods of active stars in the Kepler field as a function of spectral type and to extend reliable rotation measurements from F-, G-, and K-type to M-type stars. Using the Lomb-Scargle periodogram we searched more than 150 000 stellar light curves for periodic brightness variations.We analyzed periods between 1 and 30 days in eight consecutive Kepler quarters, where 30 days is an estimated maximum for the validity of the PDC_MAP data correction pipeline. We selected stable rotation periods, i.e., periods that do not vary from the median by more than one day in at least six of the eight quarters. We averaged the periods for each stellar spectral class according to B−V colorand compared the results to archival v sin i data, using stellar radii estimates from the Kepler Input Catalog. We report on the stable starspot rotation periods of 12 151 Kepler stars. We find good agreement between starspot velocities and v sin i data for all F-, G- and early K-type stars. The 795 M-type stars in our sample have a median rotation period of 15.4 days. We find an excess of M-type stars with periods less than 7.5 days that are potentially fast-rotating and fully convective. Measuring photometric variability in multiple Kepler quarters appears to be a straightforward and reliable way to determine the rotation periods of a large sample of active stars, including late-type stars."],["dc.identifier.doi","10.1051/0004-6361/201321912"],["dc.identifier.fs","602755"],["dc.identifier.gro","3147027"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/10138"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/4764"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","final"],["dc.notes.submitter","chake"],["dc.relation","info:eu-repo/grantAgreement/EC/FP7/267864/EU//ASTERISK"],["dc.relation.issn","0004-6361"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","Rotation periods of 12 000 main-sequence Kepler stars: Dependence on stellar spectral type and comparison with v sin i observations"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","A6"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.volume","603"],["dc.contributor.author","Nielsen, M. B."],["dc.contributor.author","Schunker, Hannah"],["dc.contributor.author","Gizon, Laurent"],["dc.contributor.author","Schou, Jesper"],["dc.contributor.author","Ball, W. H."],["dc.date.accessioned","2020-12-10T18:11:35Z"],["dc.date.available","2020-12-10T18:11:35Z"],["dc.date.issued","2017"],["dc.identifier.doi","10.1051/0004-6361/201730896"],["dc.identifier.eissn","1432-0746"],["dc.identifier.issn","0004-6361"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/74069"],["dc.notes.intern","DOI Import GROB-354"],["dc.title","Limits on radial differential rotation in Sun-like stars from parametric fits to oscillation power spectra"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","A85"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.volume","622"],["dc.contributor.author","Nielsen, M. B."],["dc.contributor.author","Gizon, Laurent"],["dc.contributor.author","Cameron, Robert H."],["dc.contributor.author","Miesch, M."],["dc.date.accessioned","2020-12-10T18:11:45Z"],["dc.date.available","2020-12-10T18:11:45Z"],["dc.date.issued","2019"],["dc.identifier.doi","10.1051/0004-6361/201834373"],["dc.identifier.eissn","1432-0746"],["dc.identifier.issn","0004-6361"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/74129"],["dc.notes.intern","DOI Import GROB-354"],["dc.title","Starspot rotation rates versus activity cycle phase: Butterfly diagrams of Kepler stars are unlike that of the Sun"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","A10"],["dc.bibliographiccitation.journal","Astronomy & Astrophysics"],["dc.bibliographiccitation.volume","582"],["dc.contributor.author","Nielsen, M. B."],["dc.contributor.author","Schunker, H."],["dc.contributor.author","Gizon, Laurent"],["dc.contributor.author","Ball, Warrick H."],["dc.date.accessioned","2017-09-07T11:48:42Z"],["dc.date.available","2017-09-07T11:48:42Z"],["dc.date.issued","2015"],["dc.identifier.doi","10.1051/0004-6361/201526615"],["dc.identifier.gro","3147029"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/12442"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/4767"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","public"],["dc.notes.submitter","chake"],["dc.publisher","EDP Sciences"],["dc.relation.issn","0004-6361"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","Constraining differential rotation of Sun-like stars from asteroseismic and starspot rotation periods"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]