skip to main content


Search for: All records

Creators/Authors contains: "Jorgenson, Regina"

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. Abstract

    We present Keck Cosmic Web Imager Lyαintegral field spectroscopy of the fields surrounding 14 damped Lyαabsorbers (DLAs) atz≈ 2. Of these 14 DLAs, nine have high metallicities ([M/H] > − 0.3), and four of those nine feature a CO-emitting galaxy at an impact parameter ≲30 kpc. Our search reaches median Lyαline flux sensitivities of ∼2 × 10−17erg s−1cm−2over apertures of ∼6 kpc and out to impact parameters of ∼50 kpc. We recover the Lyαflux of three known Lyα-emitting Hi-selected galaxies in our sample. In addition, we find two Lyαemitters at impact parameters of ≈50–70 kpc from the high-metallicity DLA atz≈ 1.96 toward QSO B0551-366. This field also contains a massive CO-emitting galaxy at an impact parameter of ≈15 kpc. Apart from the field with QSO B0551-366, we do not detect significant Lyαemission in any of the remaining eight high-metallicity DLA fields. Considering the depth of our observations and our ability to recover previously known Lyαemitters, we conclude that Hi-selected galaxies associated with high-metallicity DLAs atz≈ 2 are dusty and therefore might feature low Lyαescape fractions. Our results indicate that complementary approaches—using Lyα, CO, Hα, and [Cii] 158μm emission—are necessary to identify the wide range of galaxy types associated withz≈ 2 DLAs.

     
    more » « less
  2. Abstract

    The circumgalactic medium (CGM) plays a vital role in the formation and evolution of galaxies, acting as a lifeline between galaxies and the surrounding intergalactic medium. In this study, we leverage a unique sample of quasar pairs to investigate the properties of the CGM with absorption line tomography. We present a new sample of medium-resolution Keck/ESI, Magellan/MagE, and VLT/XSHOOTER spectra of 29 quasar pairs at redshift 2 <z< 3. We supplement the sample with additional spectra of 32 pairs from the literature, creating a catalog of 61 quasar pairs with angular separations between 1.″7 and 132.″9 and projected physical separations (r) between 14 kpc and 887 kpc. We construct a catalog of 906 metal-line absorption doublets of Civ(λλ1548, 1550) with equivalent widths ranging from 6 m Å ≤Wr,1550≤ 2053 m Å. The best-fit linear model to the log-space equivalent width frequency distribution (logf(Wr)=mlog(Wr)+b) of the sample yields coefficients ofm= −1.44 ± 0.16 andb= −0.43 ± 0.16. To constrain the projected extent of Civ, we calculate the transverse autocorrelation function. The flattening of the autocorrelation function at lowrprovides a lower limit for the coherence length of the metal enriched CGM—on the order of 200h−1comoving kpc. This physical size constraint allows us to refine our understanding of the metals in the CGM, where the extent of Civin the CGM depends on gas flows, feedback, timescale of metal injection and mixing, and the mass of the host galaxies.

     
    more » « less
  3. Abstract We present a high-resolution analysis of the host galaxy of fast radio burst (FRB) 190608, an SB(r)c galaxy at z = 0.11778 (hereafter HG 190608), to dissect its local environment and its contributions to the FRB properties. Our Hubble Space Telescope Wide Field Camera 3 ultraviolet and visible light image reveals that the subarcsecond localization of FRB 190608 is coincident with a knot of star formation (Σ SFR = 1.5 × 10 −2 M ⊙ yr −1 kpc −2 ) in the northwest spiral arm of HG 190608. Using H β emission present in our Keck Cosmic Web Imager integral field spectrum of the galaxy with a surface brightness of μ H β = ( 3.36 ± 0.21 ) × 10 − 17 erg s − 1 cm − 2 arcsec − 2 , we infer an extinction-corrected H α surface brightness and compute a dispersion measure (DM) from the interstellar medium of HG 190608 of DM Host,ISM = 94 ± 38 pc cm −3 . The galaxy rotates with a circular velocity v circ = 141 ± 8 km s −1 at an inclination i gas = 37° ± 3°, giving a dynamical mass M halo dyn ≈ 10 11.96 ± 0.08 M ⊙ . This implies a halo contribution to the DM of DM Host,Halo = 55 ± 25 pc cm −3 subject to assumptions on the density profile and fraction of baryons retained. From the galaxy rotation curve, we infer a bar-induced pattern speed of Ω p = 34 ± 6 km s −1 kpc −1 using linear resonance theory. We then calculate the maximum time since star formation for a progenitor using the furthest distance to the arm’s leading edge within the localization, and find t enc = 21 − 6 + 25 Myr. Unlike previous high-resolution studies of FRB environments, we find no evidence of disturbed morphology, emission, or kinematics for FRB 190608. 
    more » « less
  4. null (Ed.)