Gregory R. Zeimann
A5082853358- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Astrophysical Phenomena and Observations
- Astro and Planetary Science
- Radio Astronomy Observations and Technology
- CCD and CMOS Imaging Sensors
- Astrophysics and Cosmic Phenomena
- Particle Detector Development and Performance
- Photocathodes and Microchannel Plates
- Particle Accelerators and Free-Electron Lasers
- Scientific Research and Discoveries
- Pulsars and Gravitational Waves Research
- Atmospheric Ozone and Climate
- Geomagnetism and Paleomagnetism Studies
- Planetary Science and Exploration
- Spectroscopy and Laser Applications
- Remote Sensing in Agriculture
- Solar and Space Plasma Dynamics
- Calibration and Measurement Techniques
- Adaptive optics and wavefront sensing
- Neutrino Physics Research
Canada–France–Hawaii Telescope
2019-2025
The University of Texas at Austin
2016-2024
McDonald's (United States)
2023
Pennsylvania State University
2013-2017
University of California, Davis
2009-2013
Joint Institute for VLBI ERIC
2011
We analyze the star formation properties of 16 infrared-selected, spectroscopically confirmed galaxy clusters at $1 < z 1.5$ from Spitzer/IRAC Shallow Cluster Survey (ISCS). present new spectroscopic confirmation for six these high-redshift clusters, five which are $z>1.35$. Using infrared luminosities measured with deep Spitzer/MIPS observations 24 $\mu$m, along robust optical+IRAC photometric redshifts and SED-fitted stellar masses, we dust-obscured star-forming fractions, rates specific...
We present the Spitzer Extragalactic Representative Volume Survey (SERVS), an 18 deg2 medium-deep survey at 3.6 and 4.5 μm with postcryogenic Space Telescope to ≈2 μJy (AB = 23.1) depth of five highly observed astronomical fields (ELAIS-N1, ELAIS-S1, Lockman Hole, Chandra Deep Field South, XMM-LSS). SERVS is designed enable study galaxy evolution as a function environment from z ∼ 5 day first extragalactic that both large enough deep put rare objects such luminous quasars clusters ≳ 1 into...
We use 317,000 emission-line galaxies from the Sloan Digital Sky Survey to investigate line-ratio selection of active galactic nuclei (AGNs). In particular, we demonstrate that "star formation (SF) dilution" by H ii regions causes a significant bias against AGN in low-mass, blue, star-forming, disk-dominated galaxies. This is responsible for observed preference AGNs among high-mass, green, moderately bulge-dominated hosts. account and simulate intrinsic population using physically motivated...
We describe the survey design, calibration, commissioning, and emission-line detection algorithms for Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). The goal of HETDEX is to measure redshifts over a million Ly$\alpha$ emitting galaxies between 1.88<z<3.52, in 540 deg^2 area encompassing co-moving volume 10.9 Gpc^3. No pre-selection targets involved; instead measurements are accomplished via spectroscopic using suite wide-field integral field units distributed focal plane telescope....
Abstract We present the first publicly released catalog of sources obtained from Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). HETDEX is an integral field spectroscopic survey designed to measure Hubble expansion parameter and angular diameter distance at 1.88 < z 3.52 by using spatial distribution more than a million Ly α -emitting galaxies over total target area 540 deg 2 . The comes contiguous fiber spectra coverage 25 sky 2017 January through 2020 June, where object...
Abstract Atmospheric escape shapes the fate of exoplanets, with statistical evidence for transformative mass loss imprinted across mass–radius–insolation distribution. Here, we present transit spectroscopy highly irradiated, low-gravity, inflated hot Saturn HAT-P-67 b. The Habitable Zone Planet Finder spectra show a detection up to 10% absorption depth 10833 Å helium triplet. 13.8 hr on-sky integration time over 39 nights sample entire planet orbit, uncovering excess preceding by 130...
Abstract A complete understanding of the central stars planetary nebulae (CSPNe) remains elusive. Over past several decades, time-series photometry CSPNe has yielded significant results including, but not limited to, discoveries nearly 100 binary systems, insights into pulsations and winds in young white dwarfs, studies undergoing very late thermal pulses. We have undertaken a systematic study optical photometric variability cataloged CSPNe, using light curves from Zwicky Transient Facility...
We compare the star formation (SF) activity in cluster galaxies to field from z=0.3-1.5 using $Herschel$ SPIRE 250$\mu$m imaging. utilize 274 clusters IRAC Shallow Cluster Survey (ISCS) selected as rest-frame near-infrared overdensities over 9 square degree Bootes . This analysis allows us quantify evolution of SF a long redshift baseline without bias against active systems. Using stacking analysis, we determine average rates (SFRs) and specific-SFRs (SSFR=SFR/M$_{\star}$) stellar...
ABSTRACT We report the discovery of a bright ( f (250 μm)>400 mJy), multiply lensed submillimeter galaxy HERMES J105751.1+573027 in Herschel /SPIRE Science Demonstration Phase data from HerMES project. Interferometric 880 μm Submillimeter Array observations resolve at least four images with large separation ∼9″. A high-resolution adaptive optics K p image Keck/NIRC2 clearly shows strong lensing arcs. Follow-up spectroscopy gives redshift z = 2.9575, and model total magnification μ ∼ 11 ±...
We present a high-resolution radio survey of the Sloan Digital Sky Survey (SDSS) Southern Equatorial Stripe, a.k.a. Stripe 82. This 1.4 GHz was conducted with Very Large Array (VLA) primarily in A-configuration, supplemental B-configuration data to increase sensitivity extended structure. The has an angular resolution 1.8" and achieves median rms noise 52 microJy/bm over 92 deg^2. is deepest achieve this large area, filling gap phase space between small, deep large, shallow surveys. It also...
We report the discovery of an IR-selected galaxy cluster in IRAC Distant Cluster Survey (IDCS). New data from Hubble Space Telescope spectroscopically confirm IDCS J1433.2+3306 at z = 1.89 with robust spectroscopic redshifts for seven members, two which are based on 4000 Å break. Detected emission lines such as [O ii] and Hβ indicate star formation rates ≳20 M☉ yr−1 three galaxies within a 500 kpc projected radius center. The exhibits red sequence scatter color indicative redshift zf ≳ 3.5....
ABSTRACT We present post-cryogenic Spitzer imaging at 3.6 and 4.5 μ m with the Infrared Array Camera (IRAC) of /HETDEX Exploratory Large-Area (SHELA) survey. SHELA covers ≈24 deg 2 Sloan Digital Sky Survey “Stripe 82” region, falls within footprints Hobby–Eberly Telescope Dark Energy Experiment (HETDEX) Survey. The HETDEX blind R ∼ 800 spectroscopy will produce ∼200,000 redshifts from Ly α emission for galaxies in range 1.9 < z 3.5, an additional [O ii ] 0.5. When combined deep ugriz...
We present the Massive and Distant Clusters of WISE Survey (MaDCoWS), a search for galaxy clusters at 0.7<z<1.5 based upon data from Wide-field Infrared Explorer (WISE) mission. MaDCoWS is first cluster survey capable discovering massive these redshifts over full extragalactic sky. The divided into two regions -- region sky covered by Pan-STARRS (Dec>-30 degrees) remainder southern Dec<-30 degrees which shallower optical SuperCOSMOS Sky are available. In this paper we describe algorithm,...
Galaxy proto-clusters at z >~ 2 provide a direct probe of the rapid mass assembly and galaxy growth present day massive clusters. Because need precise redshifts for density mapping prevalence star formation before quenching, nearly all known to date were confirmed by spectroscopy galaxies with strong emission lines. Therefore, large emission-line surveys an efficient way identify directly. Here we report discovery large-scale structure = 2.44 in HETDEX Pilot Survey. On scale few tens Mpc...
We present the results from a Very Large Telescope/SINFONI and Keck/NIRSPEC near-infrared spectroscopic survey of 16 Lyα emitters (LAEs) at z = 2.1–2.5 in COSMOS GOODS-N fields discovered Hobby Eberly Telescope Dark Energy Experiment Pilot Survey. detect rest-frame optical nebular lines (Hα and/or [O iii] λ5007) for 10 LAEs measure physical properties, including star formation rate (SFR), gas-phase metallicity, gas mass fraction, velocity offset. find that may lie below mass–metallicity...
We present results for the assembly and star formation histories (SFHs) of massive (∼L*) red sequence galaxies (RSGs) in 11 spectroscopically confirmed, infrared-selected galaxy clusters at 1.0 < z 1.5, precursors to present-day with M ∼ 1015 M☉. Using rest-frame optical photometry, we investigate evolution color scatter RSG population, comparing models possible SFHs. In contrast studies central cluster lower redshift (z 1), these data are clearly inconsistent continued stars formed...
We report 31 GHz CARMA observations of IDCS J1426.5+3508, an infrared-selected galaxy cluster at z = 1.75. A Sunyaev-Zel'dovich decrement is detected towards this cluster, indicating a total mass M200 (4.3 +/- 1.1) x 10^{14} Msun in agreement with the approximate X-ray ~5 Msun. J1426.5+3508 by far most distant yet via effect, and massive >= 1.4 found to date. Despite mere ~1% probability finding it 8.82 deg^2 IRAC Distant Cluster Survey, not completely unexpected LCDM once area large,...
We compare the physical and morphological properties of z ~ 2 Lyman-alpha emitting galaxies (LAEs) identified in HETDEX Pilot Survey narrow band studies with those optical emission line (oELGs) via HST WFC3 infrared grism spectroscopy. Both sets extend over same range stellar mass (7.5 < logM 10.5), size (0.5 R 3.0 kpc), star-formation rate (~1 SFR 100). Remarkably, a comparison most commonly used parameters -- mass, half-light radius, UV slope, star formation rate, ellipticity, nearest...
ABSTRACT We present a detailed, multi-wavelength study of star formation (SF) and active galactic nucleus (AGN) activity in 11 near-infrared (IR) selected, spectroscopically confirmed massive (≳10 14 M ⊙ ) galaxy clusters at 1 < z 1.75. Using new deep Herschel /PACS imaging, we characterize the optical to far-IR spectral energy distributions (SEDs) for IR-luminous cluster galaxies, finding that they can, on average, be well described by field templates. Identification decomposition AGNs...
We use broadband photometry extending from the rest-frame UV to near-IR fit individual spectral energy distributions (SEDs) of 63 bright (L(Ly-alpha) > 10^43 ergs/s) Ly-alpha emitting galaxies (LAEs) in redshift range 1.9 < z 3.6. find that these LAEs are quite heterogeneous, with stellar masses span over three orders magnitude, 7.5 log M 10.5. Moreover, although most have small amounts extinction, some high-mass objects reddenings as large E(B-V) ~0.4. Interestingly, dusty optical depths...
Abstract We present the median-stacked Lyman -α ( Ly α ) surface brightness profiles of 968 spectroscopically selected emitting galaxies (LAEs) at redshifts 1.9 < z 3.5 in early data Hobby-Eberly Telescope Dark Energy Experiment. The LAEs are high-confidence detections with high signal-to-noise ratios observed good seeing conditions (point-spread function FWHM <1.″4), excluding active galactic nuclei. luminosities 10 42.4 –10 43 erg s −1 . detect faint emission radial level <?CDATA...
We present optical and near-infrared (NIR) observations of the Type Icn supernova (SN Icn) 2022ann, fifth member its newly identified class SNe. Its early spectra are dominated by narrow carbon oxygen P-Cygni features with absorption velocities 800 km/s; slower than other SNe indicative interaction a dense, H/He-poor circumstellar medium (CSM) that is outflowing typical Wolf-Rayet wind velocity $>$1000 km/s. identify helium in NIR obtained two weeks after maximum at three weeks,...
Capturing planets in the act of losing their atmospheres provides rare opportunities to probe evolution history. This analysis has been enabled by observations helium triplet at 10,833 angstrom, but past studies have focused on narrow time window right around planet’s optical transit. We monitored hot Jupiter HAT-P-32 b using high-resolution spectroscopy from Hobby-Eberly Telescope covering full orbit. detected escaping a 14σ significance,with extended leading and trailing tails spanning...
The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) is an untargeted spectroscopic survey that aims to measure the expansion rate of Universe at $z \sim 2.4$ 1% precision for both $H(z)$ and $D_A(z)$. HETDEX in process mapping excess one million Lyman Alpha emitting (LAE) galaxies a similar number lower-z as tracer large-scale structure. success measurement predicated on post-observation separation with Ly$\alpha$ emission from lower-$z$ interloping galaxies, primarily [OII], low...
We confirm the planetary nature of two gas giants discovered by TESS to transit M dwarfs with stellar companions at wide separations. TOI-3984 A ($J=11.93$) is an M4 dwarf hosting a short-period ($4.353326 \pm 0.000005$ days) giant ($M_p=0.14\pm0.03~\mathrm{M_{J}}$ and $R_p=0.71\pm0.02~\mathrm{R_{J}}$) separation white companion. TOI-5293 ($J=12.47$) M3 ($2.930289 0.000004$ ($M_p=0.54\pm0.07~\mathrm{M_{J}}$ $R_p=1.06\pm0.04~\mathrm{R_{J}}$) characterize both systems using combination...