BARYON CONTENT TO THE OUTSKIRTS OF LOW-TEMPERATURE POOR GALAXY GROUPS

Nugent, Jenna

BARYON CONTENT TO THE OUTSKIRTS OF LOW-TEMPERATURE POOR GALAXY GROUPS

dc.contributor.advisor	Dai, Xinyu
dc.contributor.author	Nugent, Jenna
dc.contributor.committeeMember	Henry, Richard
dc.contributor.committeeMember	Leighly, Karen
dc.contributor.committeeMember	Baer, Howard
dc.contributor.committeeMember	Hope, Trina
dc.date.accessioned	2019-12-16T16:12:11Z
dc.date.available	2019-12-16T16:12:11Z
dc.date.issued	2019-12-05
dc.date.manuscript	2019-12-13
dc.description.abstract	Little is known concerning the overall properties of galaxy groups, especially at large radii. A better understanding of them will constrain numerical simulations regarding their formation and evolution, as well as reveal what role they play in the Missing Baryon Problem. I will present Suzaku oﬀ-center X-ray observations of two poor galaxy groups, NGC 3402 and NGC 5129, with temperatures below 1 keV. Through spectral decomposition, I measured their surface brightnesses and temperatures out to a large fraction of their outskirts. With the reﬁned bolometric X-ray luminosities, both groups prefer L_x–T relations without a break in the group regime. Furthermore, I have determined the electron number densities and hydrostatic masses at these radii. I found that the surface brightness and electron number density proﬁles require two β model components, as well as an indication that a third β model may be needed for NGC 3402. Adding the gas mass measured from the X-ray data and stellar mass from group galaxy members, I computed baryon fractions of f_b = 0.069 ± 0.007 and f_b = 0.095 ± 0.014 for NGC 3402 and NGC 5129, respectively. Combining other poor groups with well measured X-ray emission out to their outskirts, I found an average baryon fraction extrapolated to r_500 of f_b,500 = 0.091 ± 0.005 for X-ray bright groups with temperatures between 0.8–1.3 keV, extending existing constraints to lower mass systems and indicating that signiﬁcant baryon losses exist below approximately r_500.	en_US
dc.identifier.uri	https://hdl.handle.net/11244/323238
dc.language	en_US	en_US
dc.subject	Physics, Astronomy and Astrophysics.	en_US
dc.subject	X-ray Astronomy	en_US
dc.subject	Galaxy Groups	en_US
dc.subject	Missing Baryon Problem	en_US
dc.thesis.degree	Ph.D.	en_US
dc.title	BARYON CONTENT TO THE OUTSKIRTS OF LOW-TEMPERATURE POOR GALAXY GROUPS	en_US
ou.group	College of Arts and Sciences::Homer L. Dodge Department of Physics and Astronomy	en_US