Skip to main content
Home

Navigation Menu

  • Back
  • About
    • Back
    • About

      Contact Us

      Business Address
      5241 Broad Branch Rd. NW

      Washington , DC 20015
      United States place Map
      Call Us (202) 387-640
    • Who We Are
      • Back
      • Leadership
      • Board & Advisory Committee
      • Initiatives
      • Financial Stewardship
      • Awards & Accolades
      • History
    • Connect with Us
      • Back
      • Outreach & Education
      • Newsletter
      • Yearbook
    • Working at Carnegie

    Contact Us

    Business Address
    5241 Broad Branch Rd. NW

    Washington , DC 20015
    United States place Map
    Call Us (202) 387-6400
  • Research
    • Back
    • Research Areas & Topics
    • Research Areas & Topics
      • Back
      • Research Areas
      • From genomes to ecosystems and from planets to the cosmos, Carnegie Science is an incubator for cutting-edge, interdisciplinary research.
      • Astronomy & Astrophysics
        • Back
        • Astronomy & Astrophysics
        • Astrophysical Theory
        • Cosmology
        • Distant Galaxies
        • Milky Way & Stellar Evolution
        • Planet Formation & Evolution
        • Solar System & Exoplanets
        • Telescope Instrumentation
        • Transient & Compact Objects
      • Earth Science
        • Back
        • Earth Science
        • Experimental Petrology
        • Geochemistry
        • Geophysics & Geodynamics
        • Mineralogy & Mineral Physics
      • Ecology
        • Back
        • Ecology
        • Atmospheric Science & Energy
        • Adaptation to Climate Change
        • Water Quality & Scarcity
      • Genetics & Developmental Biology
        • Back
        • Genetics & Developmental Biology
        • Adaptation to Climate Change
        • Developmental Biology & Human Health
        • Genomics
        • Model Organism Development
        • Nested Ecosystems
        • Symbiosis
      • Matter at Extreme States
        • Back
        • Matter at Extreme States
        • Extreme Environments
        • Extreme Materials
        • Mineralogy & Mineral Physics
      • Planetary Science
        • Back
        • Planetary Science
        • Astrobiology
        • Cosmochemistry
        • Mineralogy & Mineral Physics
        • Planet Formation & Evolution
        • Solar System & Exoplanets
      • Plant Science
        • Back
        • Plant Science
        • Adaptation to Climate Change
        • Nested Ecosystems
        • Photosynthesis
        • Symbiosis
    • Divisions
      • Back
      • Divisions
      • Biosphere Sciences & Engineering
        • Back
        • Biosphere Sciences & Engineering
        • About

          Contact Us

          Business Address
          5241 Broad Branch Rd. NW

          Washington , DC 20015
          United States place Map
          Call Us (202) 387-640
        • Research
        • Culture
      • Earth & Planets Laboratory
        • Back
        • Earth & Planets Laboratory
        • About

          Contact Us

          Business Address
          5241 Broad Branch Rd. NW

          Washington , DC 20015
          United States place Map
          Call Us (202) 387-640
        • Research
        • Culture
        • Campus
      • Observatories
        • Back
        • Observatories
        • About

          Contact Us

          Business Address
          5241 Broad Branch Rd. NW

          Washington , DC 20015
          United States place Map
          Call Us (202) 387-640
        • Research
        • Culture
        • Campus
    • Instrumentation
      • Back
      • Instrumentation
      • Our Telescopes
        • Back
        • Our Telescopes
        • Magellan Telescopes
        • Swope Telescope
        • du Pont Telescope
      • Observatories Machine Shop
      • EPL Research Facilities
      • EPL Machine Shop
      • Mass Spectrometry Facility
      • Advanced Imaging Facility
  • People
    • Back
    • People
      Observatory Staff

      Featured Staff Member

      Staff Member

      Staff Member

      Professional Title

      Learn More
      Observatory Staff

      Search For

    • Search All People
      • Back
      • Staff Scientists
      • Leadership
      • Biosphere Science & Engineering People
      • Earth & Planets Laboratory People
      • Observatories People
    Observatory Staff
    Dr. Allan Spradling
    Staff Scientist, Emeritus Director

    Featured Staff Member

    Allan Spradling portait

    Dr. Allan Spradling - HHMI

    Staff Scientist, Emeritus Director

    Learn More
    Observatory Staff
    Dr. Allan Spradling
    Staff Scientist, Emeritus Director

    Allan Spradling and his team focus on the biology of reproduction, particularly oogenesis — the process of egg formation.

    Search For

    Search All Staff
  • Events
    • Back
    • Events
    • Search All Events
      • Back
      • Biosphere Science & Engineering Events
      • Earth & Planets Laboratory Events
      • Observatories Events

    Upcoming Events

    Events

    Events

    Hawaiian bobtail squid
    Public Program

    The Ink-Credible Power of Symbiosis

    Margaret McFall-Ngai

    September 16

    7:00pm PDT

    A researcher conducting fieldwork at the Slave Craton, Canada
    Workshop

    TIMES Kickoff Workshop

    Jennifer Kasbohm

    August 12

    12:00pm EDT

    People sit on the shore at sunset.
    Workshop

    Seventh Workshop on Trait-based Approaches to Ocean Life

    Pacific Grove, CA

    August 4

    9:00pm PDT

  • News
    • Back
    • News
    • Search All News
      • Back
      • Biosphere Science & Engineering News
      • Earth & Planets Laboratory News
      • Observatories News
      • Carnegie Science News
    News

    Recent News

    News

    Read all News
    Image Tube Spectrograph
    Breaking News
    July 22, 2025

    Five Objects That Tell Vera Rubin’s Story

    Las Campanas Observatory
    Breaking News
    July 10, 2025

    The History of Las Campanas Observatory

    Vera Rubin at Carnegie Science’s former Department of Terrestrial Magnetism, now part of the Earth and Planets Laboratory, in 1972 usi
    Breaking News
    June 18, 2025

    10 Iconic Photographs of Vera Rubin

  • Donate
    • Back
    • Donate
      - ,

    • Make a Donation
      • Back
      • Support Scientific Research
      • The Impact of Your Gift
      • Planned Giving
    Jo Ann Eder

    I feel passionately about the power of nonprofits to bolster healthy communities.

    - Jo Ann Eder , Astronomer and Alumna

    Header Text

    Postdoctoral alumna Jo Ann Eder is committed to making the world a better place by supporting organizations, like Carnegie, that create and foster STEM learning opportunities for all. 

    Learn more arrow_forward
  • Home

Abstract
We present CO(1-0) observations of objects within the Shocked POststarburst Galaxy Survey taken with the Institut de Radioastronomie Millimetrique 30 m single dish and the Combined Array for Research for Millimeter Astronomy interferometer. Shocked poststarburst galaxies (SPOGs) represent a transitioning population of galaxies, with deep Balmer absorption (EWH delta > 5 angstrom), consistent with an intermediate-age (A-star) stellar population, and ionized gas line ratios inconsistent with pure star formation. The CO(1-0) subsample was selected from SPOGs detected by the Wide-field Infrared Survey Explorer with 22 mu m flux detected at a signal-to-noise ratio. (S/N) > 3. Of the 52 objects observed in CO(1-0), 47 are detected with S/N > 3. A large fraction (37%-46% +/- 7%) of our CO-SPOG sample were visually classified as morphologically disrupted. The H-2 masses detected were between 10(8.7-10.8) M-circle dot, consistent with the gas masses found in normal galaxies, though approximately an order of magnitude larger than the range seen in poststarburst galaxies. When comparing the 22 mu m and CO(1-0) fluxes, SPOGs diverge from the normal star-forming relation, having 22 mu m fluxes in excess of the relation by a factor of = 4.91(-0.39)(+0.42), suggestive of the presence of active galactic nuclei (AGNs). The Na I D characteristics of CO-SPOGs show that it is likely that many of these objects host interstellar winds. Objects with. large Na I D enhancements also tend to emit in the radio, suggesting possible AGN. driving of neutral winds.
View Full Publication open_in_new
Abstract
We present LZIFU (LaZy-IFU), an IDL toolkit for fitting multiple emission lines simultaneously in integral field spectroscopy (IFS) data. LZIFU is useful for the investigation of the dynamical, physical and chemical properties of gas in galaxies. LZIFU has already been applied to many world-class IFS instruments and large IFS surveys, including the Wide Field Spectrograph, the new Multi Unit Spectroscopic Explorer (MUSE), the Calar Alto Legacy Integral Field Area (CALIFA) survey, the Sydney-Australian-astronomical-observatory Multi-object Integral-field spectrograph (SAMI) Galaxy Survey. Here we describe in detail the structure of the toolkit, and how the line fluxes and flux uncertainties are determined, including the possibility of having multiple distinct kinematic components. We quantify the performance of LZIFU, demonstrating its accuracy and robustness. We also show examples of applying LZIFU to CALIFA and SAMI data to construct emission line and kinematic maps, and investigate complex, skewed line profiles presented in IFS data. The code is made available to the astronomy community through github. LZIFU will be further developed over time to other IFS instruments, and to provide even more accurate line and uncertainty estimates.
View Full Publication open_in_new
Abstract
We investigate the optical and Wide-field Survey Explorer (WISE) colors of "E+A" identified post-starburst galaxies, including a deep analysis of 190 post-starbursts detected in the 2 mu m All Sky Survey Extended Source Catalog. The post-starburst galaxies appear in both the optical green valley and the WISE Infrared Transition Zone. Furthermore, we find that post-starbursts occupy a distinct region of [3.4]-[4.6] versus [4.6]-[12] WISE colors, enabling the identification of this class of transitioning galaxies through the use of broadband photometric criteria alone. We have investigated possible causes for the WISE colors of post-starbursts by constructing a composite spectral energy distribution (SED), finding that the mid-infrared (4-12 mu m) properties of post-starbursts are consistent with either 11.3 mu m polycyclic aromatic hydrocarbon emission, or thermally pulsating asymptotic giant branch (TP-AGB) and post-AGB stars. The composite SED of extended post-starburst galaxies with 22 mu m emission detected with signal-to-noise ratio >= 3 requires a hot dust component to produce their observed rising mid-infrared SED between 12 and 22 mu m. The composite SED of WISE. 22 mu m non-detections (S/N < 3), created by stacking 22 mu m images, is also flat, requiring a hot dust component. The most likely source of the mid-infrared emission of these E+A galaxies is a buried active galactic nucleus (AGN). The inferred upper limits to the Eddington ratios of post-starbursts are 10(-2)-10(-4), with an average of 10(-3). This suggests that AGNs are not radiatively dominant in these systems. This could mean that including selections capable of identifying AGNs as part of a search for transitioning and post-starburst galaxies would create a more complete census of the transition pathways taken as a galaxy quenches its star formation.
View Full Publication open_in_new
Abstract
IC 1613 is an isolated dwarf galaxy within the Local Group. Low foreground and internal extinction, low metallicity, and low crowding make it an invaluable testbed for the calibration of the local distance ladder. We present new, high-fidelity distance estimates to IC 1613 via its Tip of the Red Giant Branch (TRGB) and its RR Lyrae (RRL) variables as part of the Carnegie-Chicago Hubble Program, which seeks an alternate local route to H-0 using Population II stars. We have measured a TRGB magnitude I-ACS(TRGB) = 20.35 +/- 0.01(stat) +/- 0.01(sys) mag using wide-field observations obtained from the IMACS camera on the Magellan-Baade telescope. We have further constructed optical and near-infrared RRL light curves using archival BI-and new H-band observations from the ACS/WFC and WFC3/IR instruments on board the Hubble Space Telescope (HST). In advance of future Gaia data releases, we set provisional values for the TRGB luminosity via the Large Magellanic Cloud and Galactic RRL zero-points via HST parallaxes. We find corresponding true distance moduli mu(TRGB)(0) = 24.30 +/- 0.03(stat) +/- 0.05(sys) mag and mu(RRL)(0) 24.28 +/- 0.04(stat+sys) mag. We compare our results to a body of recent publications on IC 1613 and find no statistically significant difference between the distances derived from Population. I and II stars.
View Full Publication open_in_new
Abstract
The Shocked POststarburst Galaxy Survey (SPOGS) aims to identify galaxies in the transitional phase between actively star-forming and quiescence with nebular lines that are excited from shocks rather than star formation processes. We explored the ultraviolet (UV) properties of objects with near-ultraviolet (NUV) and far-ultraviolet (FUV) photometry from archival GALEX data; 444 objects were detected in both bands, 365 in only the NUV, and 24 in only the FUV, for a total of 833 observed objects. We compared SPOGs to samples of star-forming galaxies (SFs), quiescent galaxies (Qs), classical E+A post-starburst galaxies, active galactic nuclei (AGN) host galaxies, and interacting galaxies. We found that SPOGs have a larger range in their FUV-NUV and NUV-r colors compared with most of the other samples, although all of our comparison samples occupied color space inside of the SPOGs region. On the basis of their UV colors, SPOGs are a heterogeneous group, possibly made up of a mixture of SFs, Qs, and/or AGN. Using Gaussian mixture models, we are able to recreate the distribution of FUV-NUV colors of SPOGs and E + A galaxies with different combinations of SFs, Qs, and AGN. We find that the UV colors of SPOGs require a > 60% contribution from SFs, with either Qs or AGN representing the remaining contribution, while UV colors of E + A galaxies required a significantly lower fraction of SFs, supporting the idea that SPOGs are at an earlier point in their transition from quiescent to star-forming than E + A galaxies.
View Full Publication open_in_new
Abstract
We demonstrate a robust method of resolving the star formation and AGN contributions to emission lines using two very well known AGN systems: NGC 1365 and NGC 1068, using the high spatial resolution data from the TYPHOON/PrISM survey. We expand the previous method of calculating the AGN fraction by using theoretical-based model grids rather than empirical points. The high spatial resolution of the TYPHOON/PrISM observations shows evidence of both star formation and AGN activity occurring in the nuclei of the two galaxies. We rebin the data to the lower resolutions, typically found in other integral field spectroscopy surveys such as SAMI, MaNGA, and CALIFA. The results show that when rebinned from the native resolution of TYPHOON (< 200 pc pixel(-1)) to 1 kpc pixel(-1), the effects include an similar to 3 kpc increase in the radius of measured AGN activity, and a factor of 2-7 increase in the detection of low surface brightness features such as shocks. All of this information is critical, because information on certain physical processes may be lost at varying resolutions. We make recommendations for analysing data at current IFU survey resolutions.
View Full Publication open_in_new
Abstract
The Carnegie-Chicago Hubble Program (CCHP) seeks to anchor the distance scale of Type la supernovae via the Tip of the Red Giant Branch (TRGB) method. Based on deep Hubble Space Telescope ACS/WFC imaging, we present an analysis of the TRGB for the metal-poor halo of NGC 1365, a giant spiral galaxy in the Fornax cluster that was host to the Type la supernova SN 2012fr. We have measured the extinction-corrected TRGB magnitude of NGC 1365 to be F814W = 27.34 +/- 0.03(stat) +/- 0.04(sys) mag. In advance of future direct calibration by Gala, we adopt a provisiona I-band TRGB luminosity set at the Large Magellanic Cloud and find a true distance modulus mu(0) = 31.29 +/- 0.04(stat) +/- 0.06(sys) mag or D = 18.1 +/- 0.3(stat) +/- 0.5(sys) Mpc. This measurement is in excellent agreement with recent Cepheid-based distances to NGC 1365 and reveals no significant difference in the distances derived from stars of Populations I and II for this galaxy. We revisit the error budget for the CCHP path to the Hubble constant based on the analysis presented here, i.e., that for one of the most distant Type la supernova hosts within our Program, and find that a 2.5% measurement is feasible with the current sample of galaxies and TRGB absolute calibration.
View Full Publication open_in_new
Abstract
Based on observations from the FourStar near-infrared camera on the 6.5 m Baade-Magellan telescope at Las Campanas, Chile, we present calibrations of the JHK luminosities of stars defining the tip of the red giant branch (TRGB) in the halo of the Local Group dwarf galaxy IC 1613. We employ metallicity-independent (rectified) T-band magnitudes-constructed using J-, H-, and K-band magnitudes and both (J - H) and (J - K) colors to flatten the upward-sloping red giant branch tips as otherwise seen in their apparent color-magnitude diagrams. We describe and quantify the advantages of working at these particular near-infrared wavelengths, which are applicable to both the Hubble Space Telescope (HST) and the James Webb Space Telescope (JWST). We also note that these same wavelengths can be accessed from the ground for an eventual tie-in to Gaia for absolute astrometry and parallaxes to calibrate the intrinsic luminosity of the TRGB. Adopting the color terms derived from the IC 1613 data, as well as the zero points from a companion study of the Large Magellanic Cloud, whose distance is anchored to the geometric distances of detached eclipsing binaries, we find a true distance modulus of 24.32. +/- 0.02. (statistical) +/- 0.05. mag (systematic) for IC 1613, which compares favorably with the recently published multi-wavelength, multi-method consensus modulus of 24.30 +/- 0.05. mag by Hatt et al.
View Full Publication open_in_new
Abstract
The Carnegie-Chicago Hubble Program is undertaking a re-calibration of the extragalactic distance scale, using SNe Ia that are tied to Tip of the Red Giant Branch (TRGB) distances to local galaxies. We present here deep Hubble Space Telescope ACS/WFC imaging of the resolved stellar populations in the metal-poor halos of the SN. Ia-host galaxies NGC 4424, NGC 4526, and NGC 4536. These three Virgo constellation galaxies are prime targets for calibrating the extragalactic distance scale given their relative proximity in the local universe and their low line-of-sight reddenings. Anchoring the TRGB zero-point to the geometric distance to the Large Magellanic Cloud via detached eclipsing binaries, we measure extinction-corrected distance moduli of 31.00 +/- 0.03(stat) +/- 0.06(sys) mag, 30.98 +/- 0.03(stat) +/- 0.06(sys) mag, and 30.99 +/- 0.03(stat) +/- 0.06(sys) mag for NGC 4424, NGC 4526, and NGC 4536, respectively, or 15.8 +/- 0.2(stat) +/- 0.4(sys) Mpc, 15.7 +/- 0.2(stat) +/- 0.4(sys) Mpc, and 15.8. +/-. 0.2stat. +/-. 0.4sys Mpc. For these three galaxies, the distances are the first that are based on the TRGB, and for NGC 4424 and NGC 4526, they are the highest-precision distances published to date, each measured to 3%. Finally, we report good agreement between our TRGB distances and the available Cepheid distances for NGC 4424 and NGC 4536, demonstrating consistency between the distance scales currently derived from stars of Population I and II.
View Full Publication open_in_new
Abstract
The Carnegie-Chicago Hubble Program (CCHP) is recalibrating the extragalactic SN Ia distance scale using exclusively Population II stars. This effort focuses on the Tip of the Red Giant Branch (TRGB) method, whose systematics are entirely independent of the Population I Cepheid-based determinations that have long served as calibrators for the SN Ia distance scale. We present deep Hubble Space Telescope imaging of the low surface density and low line-of-sight reddening halos of two galaxies, NGC 1448 and NGC 1316, each of which have been hosts to recent SN Ia events. Provisionally anchoring the TRGB zero-point to the geometric distance to the Large Magellanic Cloud derived from detached eclipsing binaries, we measure extinction-corrected distance moduli of 31.23 +/- 0.04(stat )+/- 0.06(sys) mag for NGC 1448 and 31.37 +/- 0.04(stat) +/- 0.06(sys) mag for NGC 1316, respectively, giving metric distances of 17.7 +/- 0.3(stat) +/- 0.5(sys) Mpc, and 18.8 +/- 0.3(stat) +/- 0.5(sys) Mpc. We find agreement between our result and the available Cepheid distance for NGC 1448; for NGC 1316, where there are relatively few published distances based on direct measurements, we find that our result is consistent with the published SN Ia distances whose absolute scales are set from other locally determined methods such as Cepheids. For NGC 1448 and NGC 1316, our distances are some of the most precise (and systematically accurate) measurements with errors at 1.7 (2.8)% and 1.6 (2.7)% levels, respectively.
View Full Publication open_in_new

Pagination

  • Previous page chevron_left
  • …
  • Page 793
  • Page 794
  • Page 795
  • Page 796
  • Current page 797
  • Page 798
  • Page 799
  • Page 800
  • Page 801
  • …
  • Next page chevron_right
Subscribe to

Get the latest

Subscribe to our newsletters.

Privacy Policy
Home
  • Instagram instagram
  • Twitter twitter
  • Youtube youtube
  • Facebook facebook

Science

  • Biosphere Sciences & Engineering
  • Earth & Planets Laboratory
  • Observatories
  • Research Areas
  • Strategic Initiatives

Legal

  • Financial Statements
  • Conflict of Interest Policy
  • Privacy Policy

Careers

  • Working at Carnegie
  • Scientific and Technical Jobs
  • Postdoctoral Program
  • Administrative & Support Jobs
  • Carnegie Connect (For Employees)

Contact Us

  • Contact Administration
  • Media Contacts

Business Address

5241 Broad Branch Rd. NW

Washington, DC 20015

place Map

© Copyright Carnegie Science 2025