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RESEARCH

Structure, Morphology, and dynamics of nearby galaxies:

Dr. Seigar is interested in the overall structure, morphology and dynamics of nearby galaxies, especially disk galaxies. He is involved in the Arkansas Galaxy Evolution Survey (AGES), part of which is to conduct a census of supermassive black holes in the Universe.

Selected Publications:​

  • "Determination of resonance locations in NGC 613 from morphological arguments." Seigar, Harrington & Treuthardt (2018, MNRAS)

  • "The Illustris simulation: supermassive black hole - galaxy connection beyond the bulge." Mutlu Pakdil, Seigar, Hewitt, Treuthardt, Berrier & Koval (2018, MNRAS)

  • "Revisiting the (Supermassive Black Hole Mass) - (Spiral Arm Pitch Angle) Relation: A Strong Correlation for Galaxies with Pseudobulges." Davis, Graham, & Seigar (2017, MNRAS)

  • "Searching for Intermediate Mass Black Holes in Dwarf Galaxies with Low-Luminosity AGN: A multiple-method approach." Koliopanos, Ciambur, Graham, Webb, Coriat, Mutlu-Pakdil, Davis, Godet, Barrett, & Seigar (2017, A&A)

  • "A Photometric Study of the Peculiar and Potentially Double-Ringed, Nonbarred Galaxy, PGC 1000714." Mutlu-Pakdil, Mangedarage, Seigar, & Treuthardt (2017, MNRAS).

  • "The Local Black Hole Mass Function Derived from the MBH-P and the MBH-n Relations." Mutlu-Pakdil, Seigar, & Davis (2016, ApJ).

  • "Determination of Resonance Locations in Barred Spiral Galaxies Using Multiband Photometry." Sierra, Seigar, Treuthardt, & Puerari. (2015, MNRAS).

  • "Constraining Dark Matter Halo Profiles and Galaxy Formation Models Using Spiral Arm Morphology. II. Dark and Stellar Mass Concentrations for 13 Nearby Face-On Galaxies." Seigar, Davis, Berrier, & Kennefick. (2014, ApJ).

  • "The Black Hole Mass Function Derived From Local Spiral Galaxies." Davis, Berrier, Johns, Shields, Hartley, Kennefick, Kennefick, Seigar, & Lacy. (2014, ApJ).

  • "Further Evidence for a Supermassive Black Hole Mass - Pitch Angle Relation." Berrier, Davis, Kennefick, Kennefick, Seigar, Barrows, Hartley, Shields, Bentz, & Lacy. (2013, ApJ).

  • "On the Link Between Central Black Holes, Bar Dynamics, and Dark Matter Haloes in Spiral Galaxies." Treuthardt, Seigar, Sierra, Al-Baidhany, Salo, Kennefick, Kennefick, & Lacy. (2012, MNRAS).

  • "Measurement of Galactic Logarithmic Spiral Arm Pitch Angle Using Two-dimensional Fast Fourier Transform Decomposition." Davis, Berrier, Shields, Kennefick, Kennefick, Seigar, Lacy, & Puerari. (2012, ApJS).

  • "The Carnegie-Irvine Galaxy Survey. I. Overview and Atlas of Optical Images." Ho, Li, Barth, Seigar, & Peng. (2011, ApJS).

  • "Galaxy Rotation Curves in the Context of LCDM Cosmology." Seigar & Berrier. (2011, Advances in Cosmology).

  • "A revised Mass Model for the Andromeda Galaxy." Seigar, Barth, & Bullock. (2008, MNRAS).

  • "Discovery of a relationship between spiral arm morphology and supermassive black hole mass in disk galaxies." Seigar, Kennefick, Kennefick, & Lacy. (2008, ApJL).​

  • "Discovery of Andromeda XIV: A dwarf spheroidal dynamical rogue in the Local Group." Majewski, Beaton, Patterson, Kalirai, Geha, Munoz, Seigar, Guhathakurta, Gilbert, Rich, Bullock, & Reitzel. (2007, ApJL).

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Star Formation in Galaxies:

Dr. Seigar is interested in the mechanisms responsible for the formation of stars in quiescent spiral galaxies. In the widely accepted theory of spiral density waves, triggering of star formation by shocks in spiral arms would lead to the formation of HII regions downstream of density waves. This was one of the goals of the H-alpha Galaxy Survey, in which Dr. Seigar is a co-investigator.

Selected Publications:

  • "The connection between shear and star formation in spiral galaxies." Seigar. (2005, MNRAS).

  • "The H-alpha galaxy survey. I. The galaxy sample, H-alpha narrow-band observations and star formation parameters for 334 galaxies." James et al. (Seigar 13th author). (2004, A&A).

  • "A test of arm-induced star formation in spiral galaxies from near-infrared and H-alpha imaging." Seigar & James. (2002, MNRAS).

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Clusters of Galaxies:

cD galaxies have been known to have outer stellar envelopes for many decades. This is now believed to be a manifestation of intracluster light (ICL) that Zwicky first detected in the 1950s. This intracluster light is believed to be material that is stripped tidally from cluster member galaxies as they interact and/or merge with each other. Another indication of this activity in clusters is the multiple nuclei often seen in the brightest cluster galaxies (BCGs). The Large Synoptic Survey Telescope will help us to further determine the nature of ICL.

Selected Publications:

  • "Intracluster light and the extended stellar envelopes of cD galaxies: An analytical description." Seigar, Graham, & Jerjen. (2007, MNRAS).

  • "A triple nucleus in the brightest cluster galaxy in Abell 193." Seigar, Lynam, & Chorney. (2003, MNRAS).

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