230 research outputs found
Galactic Scale Feedback Observed in the 3C 298 Quasar Host Galaxy
We present high angular resolution multi-wavelength data of the 3C 298
radio-loud quasar host galaxy (z=1.439) taken using the W.M. Keck Observatory
OSIRIS integral field spectrograph with adaptive optics, Atacama Large
Millimeter/submillimeter Array (ALMA), Hubble Space Telescope (HST) WFC3, and
the Very Large Array (VLA). Extended emission is detected in the rest-frame
optical nebular emission lines H, [OIII], H, [NII], and [SII],
as well as molecular lines CO (J=3-2) and (J=5-4). Along the path of 3C 298's
relativistic jets we detect conical outflows of ionized gas with velocities up
to 1700 km s and outflow rate of 450-1500 Myr. Near the
spatial center of the conical outflow, CO (J=3-2) emission shows a molecular
gas disc with a total molecular mass () of
6.6M. On the molecular disc's blueshifted side
we observe a molecular outflow with a rate of 2300 Myr and
depletion time scale of 3 Myr. We detect no narrow H emission in the
outflow regions, suggesting a limit on star formation of 0.3
Myrkpc. Quasar driven winds are evacuating the molecular
gas reservoir thereby directly impacting star formation in the host galaxy. The
observed mass of the supermassive black hole is M and
we determine a dynamical bulge mass of 1-1.7
M. The bulge mass of 3C 298 resides 2-2.5 orders of magnitude below
the expected value from the local M relationship. A second
galactic disc observed in nebular emission is offset from the quasar by 9 kpc
suggesting the system is an intermediate stage merger. These results show that
galactic scale negative feedback is occurring early in the merger phase of 3C
298, well before the coalescence of the galactic nuclei and assembly on the
local relationship.Comment: 23 pages, 11 figures, 4 tables, Accepted for publication in the
Astrophysical Journa
IROCKS: Spatially Resolved Kinematics of z ~ 1 Star-forming Galaxies
We present results from the Intermediate Redshift OSIRIS Chemo-Kinematic Survey (IROCKS) for sixteen z ~ 1 and one z ~ 1.4 star-forming galaxies. All galaxies were observed with OSIRIS with the laser guide star adaptive optics system at Keck Observatory. We use rest-frame nebular Hα emission lines to trace morphologies and kinematics of ionized gas in star-forming galaxies on sub-kiloparsec physical scales. We observe elevated velocity dispersions (σ ≳ 50 km s^(−1)) seen in z > 1.5 galaxies persist at z ~ 1 in the integrated galaxies. Using an inclined disk model and the ratio of v/σ, we find that 1/3 of the z ~ 1 sample are disk candidates while the other 2/3 of the sample are dominated by merger-like and irregular sources. We find that including extra attenuation toward H ii regions derived from stellar population synthesis modeling brings star formation rates (SFRs) using Hα and stellar population fit into a better agreement. We explore the properties of the compact Hα sub-component, or "clump," at z ~ 1 and find that they follow a similar size–luminosity relation as local H ii regions but are scaled-up by an order of magnitude with higher luminosities and sizes. Comparing the z ~ 1 clumps to other high-redshift clump studies, we determine that the clump SFR surface density evolves as a function of redshift. This suggests clump formation is directly related to the gas fraction in these systems and may support disk fragmentation as their formation mechanism since gas fraction scales with redshift
Ursinus College Alumni Journal, Spring 1947
It\u27s time to vote • President\u27s page • News from the campus: Club meetings; Debating; Forum Committee; Curtain Club; YM and YW; Men\u27s sports; Women\u27s sports; New coach appointed; May Day; Alumni Day • Christian education in China • Around town • Ursinus professor honored • Tribute to Dean Kline • News about ourselves • Function of an alumni association • Reunion abroad • Necrology • War Memorial Committee requests expression of opinion from alumni • Alumni Association nomineeshttps://digitalcommons.ursinus.edu/alumnijournal/1030/thumbnail.jp
Cold Mode Gas Accretion on Two Galaxy Groups at z2
We present Keck Cosmic Web Imager (KCWI) integral field spectroscopy (IFS)
observations of rest-frame UV emission lines , C IV 1548 \AA, 1550\AA and He II 1640 \AA observed in the circumgalactic
medium (CGM) of two radio-loud quasar host galaxies. We detect extended
emission on 80-90 kpc scale in in both systems with C IV, and He
II emission also detected out to 30-50 kpc. All emission lines show kinematics
with a blue and redshifted gradient pattern consistent with velocities seen in
massive dark matter halos and similar to kinematic patterns of inflowing gas
seen in hydrodynamical simulations. Using the kinematics of both resolved emission and absorption, we can confirm that both kinematic
structures are associated with accretion. Combining the KCWI data with
molecular gas observations with Atacama Large Millimeter/submillimeter Array
(ALMA) and high spatial resolution of ionized gas with Keck OSIRIS, we find
that both quasar host galaxies reside in proto-group environments at . We
estimate M of warm-ionized gas within 30-50 kpc from
the quasar that is likely accreting onto the galaxy group. We estimate inflow
rates of 60-200 Myr, within an order of magnitude of the outflow
rates in these systems. In the 4C 09.17 system, we detect narrow gas streams
associated with satellite galaxies, potentially reminiscent of ram-pressure
stripping seen in local galaxy groups and clusters. We find that the quasar
host galaxies reside in dynamically complex environments, with ongoing mergers,
gas accretion, ISM stripping, and outflows likely playing an important role in
shaping the assembly and evolution of massive galaxies at cosmic noon.Comment: 24 pages, 11 figures, 6 tabes. Accepted for publication in MNRA
Ursinus College Alumni Journal, Spring 1944
Editor\u27s page: Regrets and best wishes; Thank you for writing; Don\u27t forget to vote • President\u27s page • Our war correspondents • Resignation of Jing Johnson • Commencement • Opening of new term • Forums • Men\u27s sports • Messiah • Dr. Haines visits campus • Alumni news • Letters to the alumni • Women\u27s sports • Prominent alumni pass away: Dr. Stibitz; Congressman Ditter dies • Supply store • Men and women in the service • Navy needs officers • Library receives gifts • Alumni association nomineeshttps://digitalcommons.ursinus.edu/alumnijournal/1020/thumbnail.jp
Ursinus College Alumni Journal, Winter 1946
Dean • President\u27s page • Record enrollment in 76th year • Necrology • Dean Kline dies in 83rd year • Livingood honored • Dr. Niblo attends Episcopal convention • Music room developed • Faculty increased • Revue of sports • Seeders appointed head basketball coach • Student activities • Letters to the alumni • Old Timers\u27 Day • Alumni committees appointed • Re-education of Germany • News about ourselves • Dr. Haines: Teacher and author • News around town • Recipient of Rotary Club award • Dr. Markley completes term of service • 1946 and football • As the placement office sees us • Men\u27s basketball schedulehttps://digitalcommons.ursinus.edu/alumnijournal/1026/thumbnail.jp
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