%0 Generic %1 nugent2017suzaku %A Nugent, Jenna M. %A Dai, Xinyu %A Sun, Ming %D 2017 %K emission group xray %T $Suzaku$ Measurements of Hot Halo Emission at Outskirts for Two Poor Galaxy Groups: NGC 3402 and NGC 5129 %U http://arxiv.org/abs/1704.08266 %X We present $Suzaku$ off-center observations of two poor galaxy groups, NGC 3402 and NGC 5129, with temperatures below 1 keV. Through spectral decomposition, we measure their surface brightnesses and temperatures out to 330 and 680 times the critical density of the universe for NGC 3402 and NGC 5129, respectively. These quantities are consistent with extrapolations from existing inner measurements of the two groups. With the refined X-ray luminosities, both groups prefer $L_X-T$ relations without a break in the group regime. Furthermore, we measure the electron number densities and hydrostatic masses at these radii. We find that the electron number density profiles require three $\beta$ model components, with nearly flat slopes in the 3$^rd$ $\beta$ component for both groups. However, we find the effective slope in the outskirts to be $\beta_out$ = 0.59 and 0.49 for NGC 3402 and NGC 5129, respectively. Adding the gas mass measured from the X-ray data and stellar mass from group galaxy members, we measure baryon fractions of $f_b$ = 0.113 $\pm$ 0.013 and 0.091 $\pm$ 0.006 for NGC 3402 and NGC 5129, respectively. Combining other poor groups with well measured X-ray emission to the outskirts, we find an average baryon fraction of $f_b,ave$ = 0.100 $\pm$ 0.004 for X-ray bright groups with temperatures between 0.8$-$1.3 keV, extending existing constraints to lower mass systems.

@misc{nugent2017suzaku, abstract = {We present $Suzaku$ off-center observations of two poor galaxy groups, NGC 3402 and NGC 5129, with temperatures below 1 keV. Through spectral decomposition, we measure their surface brightnesses and temperatures out to 330 and 680 times the critical density of the universe for NGC 3402 and NGC 5129, respectively. These quantities are consistent with extrapolations from existing inner measurements of the two groups. With the refined X-ray luminosities, both groups prefer $L_X-T$ relations without a break in the group regime. Furthermore, we measure the electron number densities and hydrostatic masses at these radii. We find that the electron number density profiles require three $\beta$ model components, with nearly flat slopes in the 3$^{rd}$ $\beta$ component for both groups. However, we find the effective slope in the outskirts to be $\beta_{out}$ = 0.59 and 0.49 for NGC 3402 and NGC 5129, respectively. Adding the gas mass measured from the X-ray data and stellar mass from group galaxy members, we measure baryon fractions of $f_b$ = 0.113 $\pm$ 0.013 and 0.091 $\pm$ 0.006 for NGC 3402 and NGC 5129, respectively. Combining other poor groups with well measured X-ray emission to the outskirts, we find an average baryon fraction of $f_{b,ave}$ = 0.100 $\pm$ 0.004 for X-ray bright groups with temperatures between 0.8$-$1.3 keV, extending existing constraints to lower mass systems.}, added-at = {2017-04-28T10:31:46.000+0200}, author = {Nugent, Jenna M. and Dai, Xinyu and Sun, Ming}, biburl = {https://www.bibsonomy.org/bibtex/23022c6b41d91523f6a59272d5495a0e1/miki}, description = {[1704.08266] $Suzaku$ Measurements of Hot Halo Emission at Outskirts for Two Poor Galaxy Groups: NGC 3402 and NGC 5129}, interhash = {03facdb044aaa1b8ee6bf28e73671efc}, intrahash = {3022c6b41d91523f6a59272d5495a0e1}, keywords = {emission group xray}, note = {cite arxiv:1704.08266Comment: 34 pages, 12 figures and 9 tables}, timestamp = {2017-04-28T10:31:46.000+0200}, title = {$Suzaku$ Measurements of Hot Halo Emission at Outskirts for Two Poor Galaxy Groups: NGC 3402 and NGC 5129}, url = {http://arxiv.org/abs/1704.08266}, year = 2017 }