Liverpool Skyline

Astrophysics Research Institute

Dr Christopher Usher

Dr Christopher Usher

Telephone: 0151 231 2917

ORCID

Publications

Journal article

Kamann S, Bastian N, Gossage S, Baade D, Cabrera-Ziri I, Costa GD, Mink SED, Georgy C, Giesers B, Göttgens F, Hilker M, Husser T-O, Lardo C, Larsen S, Mackey D, Martocchia S, Mucciarelli A, Platais I, Roth MM, Salaris M, Usher C, Yong D. 2020. How stellar rotation shapes the colour magnitude diagram of the massive intermediate-age star cluster NGC 1846 Monthly Notices of the Royal Astronomical Society, 492 :2177-2192 DOI Author Url Publisher Url Public Url

Pfeffer J, Bastian N, Kruijssen JMD, Reina-Campos M, Crain RA, Usher C. 2019. Young star cluster populations in the E-MOSAICS simulations Monthly Notices of the Royal Astronomical Society, 490 :1714-1733 DOI Author Url Publisher Url Public Url

Usher C, Brodie JP, Forbes DA, Romanowsky AJ, Strader J, Pfeffer J, Bastian N. 2019. The SLUGGS Survey: Measuring globular cluster ages using both photometry and spectroscopy Monthly Notices of the Royal Astronomical Society, 490 :491-501 DOI Author Url Publisher Url Public Url

Baumgardt H, He C, Sweet SM, Drinkwater M, Sollima A, Hurley J, Usher C, Kamann S, Dalgleish H, Dreizler S, Husser T-O. 2019. No evidence for intermediate-mass black holes in the globular clusters omega Cen and NGC 6624 MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 488 :5340-5351 DOI Author Url Publisher Url Public Url

Bastian N, Usher C, Kamann S, Lardo C, Larsen SS, Cabrera-Ziri I, Chantereau W, Martocchia S, Salaris M, Schiavon RP, Asa'd R, Hilker M. 2019. Multiple populations in integrated light spectroscopy of intermediate-age clusters MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 489 :L80-L85 DOI Author Url Publisher Url Public Url

Hollyhead K, Martocchia S, Lardo C, Bastian N, Kacharov N, Niederhofer F, Cabrera-Ziri I, Dalessandro E, Mucciarelli A, Salaris M, Usher C. 2019. Spectroscopic detection of multiple populations in the er Hodge 6 in the LMC Monthly Notices of the Royal Astronomical Society, 484 :4718-4725 DOI Author Url Public Url

Usher C, Beckwith T, Bellstedt S, Alabi A, Chevalier L, Pastorello N, Cerulo P, Dalgleish HS, Fraser-McKelvie A, Kamann S, Penny S, Foster C, McDermid R, Schiavon RP, Villaume A. 2019. The WAGGS project - II. The reliability of the calcium triplet as a metallicity indicator in integrated stellar light MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 482 :1275-1303 DOI Author Url Publisher Url Public Url

Bastian N, Kamann S, Cabrera-Ziri I, Georgy C, Ekström S, Charbonnel C, Ovelar MDJ, Usher C. 2018. Extended Main Sequence Turnoffs in Open Clusters as Seen by Gaia: I. NGC 2818 and the Role of Stellar Rotation Monthly Notices of the Royal Astronomical Society, 480 :3739-3746 DOI Author Url Publisher Url Public Url

Kamann S, Bastian N, Husser T-O, Martocchia S, Usher C, den Brok M, Dreizler S, Kelz A, Krajnovic D, Richard J, Steinmetz M, Weilbacher PM. 2018. Cluster kinematics and stellar rotation in NGC 419 with MUSE and adaptive optics Monthly Notices of the Royal Astronomical Society, 480 :1689-1695 DOI Author Url Publisher Url Public Url

Martocchia S, Niederhofer F, Dalessandro E, Bastian N, Kacharov N, Usher C, Cabrera-Ziri I, Lardo C, Cassisi S, Geisler D, Hilker M, Hollyhead K, Kozhurina-Platais V, Larsen S, Mackey D, Mucciarelli A, Platais I, Salaris M. 2018. The search for multiple populations in Magellanic Cloud clusters - IV. Coeval multiple stellar populations in the young star cluster NGC 1978 Monthly Notices of the Royal Astronomical Society, 477 :4696-4705 DOI Author Url Publisher Url Public Url

Chantereau W, Usher C, Bastian N. 2018. Multiple populations within globular clusters in Early-type galaxies Exploring their effect on stellar initial mass function estimates Monthly Notices of the Royal Astronomical Society, 478 DOI Author Url Publisher Url Public Url

Martocchia S, Cabrera-Ziri I, Lardo C, Dalessandro E, Bastian N, Kozhurina-Platais V, Usher C, Niederhofer F, Cordero M, Geisler D, Hollyhead K, Kacharov N, Larsen S, Li C, Mackey D, Hilker M, Mucciarelli A, Platais I, Salaris M. 2018. Age as a Major Factor in the Onset of Multiple Populations in Stellar Clusters Monthly Notices of the Royal Astronomical Society, 473 :2688-2700 DOI Author Url Publisher Url Public Url

Usher C, Pastorello N, Bellstedt S, Alabi A, Cerulo P, Chevalier L, Fraser-McKelvie A, Penny S, Foster C, McDermid RM, Schiavon RP, Villaume A. 2017. The WAGGS project - I. The WiFeS Atlas of Galactic Globular cluster Spectra MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 468 :3828-3849 DOI Author Url Publisher Url Public Url

Martocchia S, Bastian N, Usher C, Kozhurina-Platais V, Niederhofer F, Cabrera-Ziri I, Dalessandro E, Hollyhead K, Kacharov N, Lardo C, Larsen S, Mucciarelli A, Platais I, Salaris M, Cordero M, Geisler D, Hilker M, Li C, Mackey D. 2017. The search for multiple populations in Magellanic Cloud Clusters - III. No evidence for multiple populations in the SMC cluster NGC 419 MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 468 :3150-3158 DOI Author Url Publisher Url Public Url

Forbes DA, Alabi A, Brodie JP, Romanowsky AJ, Strader J, Foster C, Usher C, Spitler L, Bellstedt S, Pastorello N, Villaume A, Wasserman A, Pota V. 2017. The SLUGGS Survey: A Catalog of Over 4000 Globular Cluster Radial Velocities in 27 Nearby Early-type Galaxies ASTRONOMICAL JOURNAL, 153 DOI Author Url Publisher Url Public Url

Forbes DA, Sinpetru L, Savorgnan G, Romanowsky AJ, Usher C, Brodie J. 2017. The SLUGGS Survey: stellar masses and effective radii of early-type galaxies from Spitzer Space Telescope 3.6$μ$m imaging Monthly Notices of the Royal Astronomical Society, 464 :4611-4623 DOI Author Url Publisher Url Public Url

Alabi AB, Forbes DA, Romanowsky AJ, Brodie JP, Strader J, Joachim J, Pota V, Pastorello N, Usher CG, Spitler LR, Jennings ZG, Villaume A, Kartha S. 2016. The SLUGGS survey: the mass distribution in early-type galaxies within five effective radii and beyond Monthly Notices of the Royal Astronomical Society, 460 :3838-3860 DOI Author Url Publisher Url Public Url

Forbes DA, Alabi A, Romanowsky AJ, Brodie JP, Strader J, Usher CG, Pota V. 2016. The SLUGGS survey: globular clusters and the dark matter content of early-type galaxies Monthly Notices of the Royal Astronomical Society: Letters, 458 :L44-L48 DOI Author Url Publisher Url Public Url

Forbes DA, Romanowsky AJ, Pastorello N, Foster C, Brodie JP, Strader J, Usher C, Pota V. 2016. The SLUGGS survey: the assembly histories of individual early-type galaxies MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 457 :1242-1256 DOI Author Url Publisher Url Public Url

Foster C, Pastorello N, Roediger J, Brodie JP, Forbes DA, Kartha SS, Pota V, Romanowsky AJ, Spitler LR, Strader J, Usher C, Arnold JA. 2016. The SLUGGS Survey: stellar kinematics, kinemetry and trends at large radii in 25 early-type galaxies MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 457 :147-171 DOI Author Url Publisher Url Public Url

Alabi AB, Foster C, Forbes DA, Romanowsky AJ, Pastorello N, Brodie JP, Spitler LR, Strader J, Usher C. 2015. The SLUGGS survey: globular cluster kinematics in a 'double sigma' galaxy - NGC 4473 MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 452 :2208-2219 DOI Author Url Publisher Url

Forbes DA, Pastorello N, Romanowsky AJ, Usher C, Brodie JP, Strader J. 2015. The SLUGGS survey: inferring the formation epochs of metal-poor and metal-rich globular clusters MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 452 :1045-1051 DOI Author Url Publisher Url

Pastorello N, Forbes DA, Usher C, Brodie JP, Romanowsky AJ, Strader J, Spitler LR, Alabi AB, Foster C, Jennings ZG, Kartha SS, Pota V. 2015. The SLUGGS survey: combining stellar and globular cluster metallicities in the outer regions of early-type galaxies MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 451 :2625-2639 DOI Author Url

Pota V, Brodie JP, Bridges T, Strader J, Romanowsky AJ, Villaume A, Jennings Z, Faifer FR, Pastorello N, Forbes DA, Campbell A, Usher C, Foster C, Spitler LR, Caldwell N, Forte JC, Norris MA, Zepf SE, Beasley MA, Gebhardt K, Hanes DA, Sharples RM, Arnold JA. 2015. A SLUGGS and Gemini/GMOS combined study of the elliptical galaxy M60: wide-field photometry and kinematics of the globular cluster system MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 450 :1962-1983 DOI Author Url Publisher Url

Cappellari M, Romanowsky AJ, Brodie JP, Forbes DA, Strader J, Foster C, Kartha SS, Pastorello N, Pota V, Spitler LR, Usher C, Arnold JA. 2015. SMALL SCATTER AND NEARLY ISOTHERMAL MASS PROFILES TO FOUR HALF-LIGHT RADII FROM TWO-DIMENSIONAL STELLAR DYNAMICS OF EARLY-TYPE GALAXIES ASTROPHYSICAL JOURNAL LETTERS, 804 DOI Author Url Publisher Url

Usher C, Forbes DA, Brodie JP, Romanowsky AJ, Strader J, Conroy C, Foster C, Pastorello N, Pota V, Arnold JA. 2015. The SLUGGS survey: globular cluster stellar population trends from weak absorption lines in stacked spectra MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 446 :369-390 DOI Author Url Publisher Url

Brodie JP, Romanowsky AJ, Strader J, Forbes DA, Foster C, Jennings ZG, Pastorello N, Pota V, Usher C, Blom C, Kader J, Roediger JC, Spitler LR, Villaume A, Arnold JA, Kartha SS, Woodley KA. 2014. THE SAGES LEGACY UNIFYING GLOBULARS AND GALAXIES SURVEY (SLUGGS): SAMPLE DEFINITION, METHODS, AND INITIAL RESULTS ASTROPHYSICAL JOURNAL, 796 DOI Author Url Publisher Url

Arnold JA, Romanowsky AJ, Brodie JP, Forbes DA, Strader J, Spitler LR, Foster C, Blom C, Kartha SS, Pastorello N, Pota V, Usher C, Woodley KA. 2014. THE SLUGGS SURVEY: WIDE-FIELD STELLAR KINEMATICS OF EARLY-TYPE GALAXIES ASTROPHYSICAL JOURNAL, 791 DOI Author Url Publisher Url

Pastorello N, Forbes DA, Foster C, Brodie JP, Usher C, Romanowsky AJ, Strader J, Arnold JA. 2014. The SLUGGS survey: exploring the metallicity gradients of nearby early-type galaxies to large radii MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 442 :1003-1039 DOI Author Url Publisher Url

Penny SJ, Forbes DA, Strader J, Usher C, Brodie JP, Romanowsky AJ. 2014. Ultracompact dwarfs in the Perseus Cluster: UCD formation via tidal stripping MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 439 :3808-3816 DOI Author Url Publisher Url

Usher C, Forbes DA, Spitler LR, Brodie JP, Romanowsky AJ, Strader J, Woodley KA. 2013. The SLUGGS Survey: wide field imaging of the globular cluster system of NGC 4278 MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 436 :1172-1190 DOI Author Url Publisher Url

Forbes DA, Pota V, Usher C, Strader J, Romanowsky AJ, Brodie JP, Arnold JA, Spitler LR. 2013. Filling the gap: a new class of old star cluster? MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 435 :L6-L10 DOI Author Url Publisher Url

Strader J, Seth AC, Forbes DA, Fabbiano G, Romanowsky AJ, Brodie JP, Conroy C, Caldwell N, Pota V, Usher C, Arnold JA. 2013. THE DENSEST GALAXY ASTROPHYSICAL JOURNAL LETTERS, 775 DOI Author Url Publisher Url

Pota V, Forbes DA, Romanowsky AJ, Brodie JP, Spitler LR, Strader J, Foster C, Arnold JA, Benson A, Blom C, Hargis JR, Rhode KL, Usher C. 2013. The SLUGGS Survey: kinematics for over 2500 globular clusters in 12 early-type galaxies MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 428 :389-420 DOI Author Url Publisher Url

Brodie JP, Usher C, Conroy C, Strader J, Arnold JA, Forbes DA, Romanowsky AJ. 2012. THE SLUGGS SURVEY: NGC 3115, A CRITICAL TEST CASE FOR METALLICITY BIMODALITY IN GLOBULAR CLUSTER SYSTEMS ASTROPHYSICAL JOURNAL LETTERS, 759 DOI Author Url Publisher Url

Usher C, Forbes DA, Brodie JP, Foster C, Spitler LR, Arnold JA, Romanowsky AJ, Strader J, Pota V. 2012. The SLUGGS survey: calcium triplet-based spectroscopic metallicities for over 900 globular clusters MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 426 :1475-1495 DOI Author Url Publisher Url

Bastian NJ. A high fraction of Be stars in young massive clusters: evidence for a large population of near-critically rotating stars Monthly Notices of the Royal Astronomical Society, DOI Author Url Publisher Url Public Url

Ellison SL, Prochaska JX, Hennawi J, Lopez S, Benn CR, Usher CG, Wolfe AM, Russell DR. The nature of proximate damped Lyman alpha systems DOI Author Url Publisher Url

Usher C, Pfeffer J, Bastian N, Kruijssen JMD, Crain RA, Reina-Campos M. The origin of the 'blue tilt' of globular cluster populations in the E-MOSAICS simulations Monthly Notices of the Royal Astronomical Society, DOI Author Url Publisher Url Public Url

Martocchia S, Dalessandro E, Lardo C, Cabrera-Ziri I, Bastian N, Kozhurina-Platais V, Salaris M, Chantereau W, Geisler D, Hilker M, Kacharov N, Larsen S, Mackey D, Mucciarelli A, Niederhofer F, Platais I, Usher C. The search for multiple populations in Magellanic Clouds clusters - V. Correlation between cluster age and abundance spreads Monthly Notices of the Royal Astronomical Society, DOI Author Url Publisher Url Public Url