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The Rotation and Other Properties of Comet 49P/Arend-Rigaux, 1984 - 2012

ArXiv 1709.06089 (2017)

Authors:

Nora Eisner, Matthew M Knight, David G Schleicher

Galaxy Zoo and SpArcFiRe: Constraints on spiral arm formation mechanisms from spiral arm number and pitch angles

Monthly Notices of the Royal Astronomical Society 91探花 University Press 472:2 (2017) 2263-2279

Authors:

RE Hart, SP Bamford, WB Hayes, CN Cardamone, WC Keel, Sandor J Kruk, Christopher Lintott, KL Masters, BD Simmons, RJ Smethurst

Abstract:

In this paper we study the morphological properties of spiral galaxies, including measurements of spiral arm number and pitch angle. Using Galaxy Zoo 2, a stellar mass-complete sample of 6,222 SDSS spiral galaxies is selected. We use the machine vision algorithm SpArcFiRe to identify spiral arm features and measure their associated geometries. A 91探花 vector machine classifier is employed to identify reliable spiral features, with which we are able to estimate pitch angles for half of our sample. We use these machine measurements to calibrate visual estimates of arm tightness, and hence estimate pitch angles for our entire sample. The properties of spiral arms are compared with respect to various galaxy properties. The star formation properties of galaxies vary significantly with arm number, but not pitch angle. We find that galaxies hosting strong bars have spiral arms substantially (4-6) looser than unbarred galaxies. Accounting for this, spiral arms associated with many-arm structures are looser (by 2) than those in two-arm galaxies. In contrast to this average trend, galaxies with greater bulge-to-total stellar mass ratios display both fewer and looser spiral arms. This effect is primarily driven by the galaxy disc, such that galaxies with more massive discs contain more spiral arms with tighter pitch angles. This implies that galaxy central mass concentration is not the dominant cause of pitch angle and arm number variations between galaxies, which in turn suggests that not all spiral arms are governed by classical density waves or modal theories.

Galaxy Zoo: Major Galaxy Mergers Are Not a Significant Quenching Pathway

ASTROPHYSICAL JOURNAL 845:2 (2017) ARTN 145

Authors:

AK Weigel, K Schawinski, N Caplar, A Carpineti, RE Hart, S Kaviraj, WC Keel, SJ Kruk, CJ Lintott, RC Nichol, BD Simmons, RJ Smethurst

Large Synoptic Survey Telescope Galaxies Science Roadmap

(2017)

Authors:

Brant E Robertson, Manda Banerji, Michael C Cooper, Roger Davies, Simon P Driver, Annette MN Ferguson, Henry C Ferguson, Eric Gawiser, Sugata Kaviraj, Johan H Knapen, Chris Lintott, Jennifer Lotz, Jeffrey A Newman, Dara J Norman, Nelson Padilla, Samuel J Schmidt, Graham P Smith, J Anthony Tyson, Aprajita Verma, Idit Zehavi, Lee Armus, Camille Avestruz, L Felipe Barrientos, Rebecca AA Bowler, Malcom N Bremer, Christopher J Conselice, Jonathan Davies, Ricardo Demarco, Mark E Dickinson, Gaspar Galaz, Andrea Grazian, Benne W Holwerda, Matt J Jarvis, Vishal Kasliwal, Ivan Lacerna, Jon Loveday, Phil Marshall, Emiliano Merlin, Nicola R Napolitano, Thomas H Puzia, Aaron Robotham, Samir Salim, Mauro Sereno, Gregory F Snyder, John P Stott, Patricia B Tissera, Norbert Werner, Peter Yoachim, Kirk D Borne, Members of the LSST Galaxies Science Collaboration

Large sSynoptic Survey Telescope Galaxies Science Roadmap

(2017)

Authors:

BE Robertson, M Banerji, MC Cooper, Roger Davies, SP Driver, Ferguson, HC Ferguson, E Gawiser, S Kaviraj, JH Knapen, Chris Lintott, J Lotz, JA Newman, DJ Norman, N Padilla, SJ Schmidt, GP Smith, JA Tyson, Aprajita Verma, I Zehavi, L Armus, C Avestruz, LF Barrientos, Rebecca AA Bowler, MN Bremer, CJ Conselice, J Davies, R Demarco, ME Dickinson, G Galaz, A Grazian, BW Holwerda, Matthew Jarvis, V Kasliwal, I Lacerna, J Loveday, P Marshall, E Merlin, NR Napolitano, TH Puzia, A Robotham, S Salim, M Sereno, GF Snyder, JP Stott, PB Tissera, N Werner, P Yoachim, KD Borne

Abstract:

The Large Synoptic Survey Telescope (LSST) will enable revolutionary studies of galaxies, dark matter, and black holes over cosmic time. The LSST Galaxies Science Collaboration has identified a host of preparatory research tasks required to leverage fully the LSST dataset for extragalactic science beyond the study of dark energy. This Galaxies Science Roadmap provides a brief introduction to critical extragalactic science to be conducted ahead of LSST operations, and a detailed list of preparatory science tasks including the motivation, activities, and deliverables associated with each. The Galaxies Science Roadmap will serve as a guiding document for researchers interested in conducting extragalactic science in anticipation of the forthcoming LSST era.