221 research outputs found

    Galactic Scale Feedback Observed in the 3C 298 Quasar Host Galaxy

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    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 Hβ\beta, [OIII], Hα\alpha, [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−1^{-1} and outflow rate of 450-1500 M⊙_\odotyr−1^{-1}. Near the spatial center of the conical outflow, CO (J=3-2) emission shows a molecular gas disc with a total molecular mass (MH2\rm M_{H_{2}}) of 6.6±0.36×109\pm0.36\times10^{9}M⊙_{\odot}. On the molecular disc's blueshifted side we observe a molecular outflow with a rate of 2300 M⊙_\odotyr−1^{-1} and depletion time scale of 3 Myr. We detect no narrow Hα\alpha emission in the outflow regions, suggesting a limit on star formation of 0.3 M⊙_\odotyr−1^{-1}kpc−2^{-2}. 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 109.37−9.5610^{9.37-9.56}M⊙_{\odot} and we determine a dynamical bulge mass of 1-1.7×1010R1.6kpc\rm\times10^{10}\frac{R}{1.6 kpc} M⊙_{\odot}. The bulge mass of 3C 298 resides 2-2.5 orders of magnitude below the expected value from the local Mbulge−MBH\rm_{bulge}-M_{BH} 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

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    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

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    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 z∼\sim2

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    We present Keck Cosmic Web Imager (KCWI) integral field spectroscopy (IFS) observations of rest-frame UV emission lines Lyα\rm Ly\alpha, C IV λλ\lambda \lambda 1548 \AA, 1550\AA and He II 1640 \AA observed in the circumgalactic medium (CGM) of two z=2z=2 radio-loud quasar host galaxies. We detect extended emission on 80-90 kpc scale in Lyα\rm Ly\alpha 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 Lyα\rm Ly\alpha 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 z=2z=2. We estimate 1−6×10101-6\times10^{10}M⊙_\odot 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 M⊙_\odotyr−1^{-1}, 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

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    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

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    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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