A5065423164- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Galaxies: Formation, Evolution, Phenomena
- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Pulsars and Gravitational Waves Research
- Astrophysics and Cosmic Phenomena
- Geophysics and Gravity Measurements
- Astrophysics and Star Formation Studies
- Spectroscopy and Laser Applications
- Optical Network Technologies
- Radio Astronomy Observations and Technology
- Nitric Oxide and Endothelin Effects
- Adaptive optics and wavefront sensing
- Photocathodes and Microchannel Plates
- Cardiovascular Function and Risk Factors
- Particle accelerators and beam dynamics
- Particle Accelerators and Free-Electron Lasers
- Calibration and Measurement Techniques
- History and Developments in Astronomy
- Infrared Target Detection Methodologies
- Geophysics and Sensor Technology
- Advanced Fluorescence Microscopy Techniques
- Ionosphere and magnetosphere dynamics
University of Wisconsin–Milwaukee
2016-2021
Indiana University Bloomington
2013-2021
University of Wisconsin System
2017
Merging neutron stars offer an exquisite laboratory for simultaneously studying strong-field gravity and matter in extreme environments. We establish the physical association of electromagnetic counterpart EM170817 to gravitational waves (GW170817) detected from merging stars. By synthesizing a panchromatic dataset, we demonstrate that are long-sought production site forging heavy elements by r-process nucleosynthesis. The weak gamma-rays seen dissimilar classical short gamma-ray bursts with...
The Zwicky Transient Facility (ZTF) is a new robotic time-domain survey currently in progress using the Palomar 48-inch Schmidt Telescope. ZTF uses 47 square degree field with 600 megapixel camera to scan entire northern visible sky at rates of ~3760 degrees/hour median depths g ~ 20.8 and r 20.6 mag (AB, 5sigma 30 sec). We describe Science Data System that housed IPAC, Caltech. This comprises data-processing pipelines, alert production system, data archive, user interfaces for accessing...
We present results from ground-based optical imaging of a low-mass dwarf galaxy discovered by the ALFALFA 21-cm HI survey. Broadband (BVR) data obtained with WIYN 3.5-m telescope at Kitt Peak National Observatory (KPNO) are used to construct color-magnitude diagrams galaxy's stellar population down V_0 ~ 25. also use narrowband H-alpha KPNO 2.1-m identify an HII region in galaxy. these constrain distance be between 1.5 and 2.0 Mpc. This places Leo P within Local Volume but beyond Group. Its...
The intermediate Palomar Transient Factory (iPTF) autonomously responded to and promptly tiled the error region of first gravitational wave event GW150914 search for an optical counterpart. Only a small fraction total localized was immediately visible in Northern night sky, due both sun-angle elevation constraints. Here, we report on transient candidates identified rapid follow-up undertaken determine nature each candidate. Even area imaged 126 sq deg, after extensive filtering, 8 were...
ABSTRACT We analyze the relationships between atomic, neutral hydrogen (H i ) and star formation (SF) in 12 low-mass SHIELD galaxies. compare high spectral (∼0.82 km s −1 ch spatial resolution (physical resolutions of 160–640 pc) H imaging from VLA with α far-ultraviolet imaging. quantify degree co-spatiality star-forming regions column densities. calculate global efficiencies (SFE; <?CDATA ${{\rm{\Sigma }}}_{\mathrm{SFR}}$?> / }}}_{{\rm{H}}{\rm{I}}}$?> examine among SFE mass, density, rate...
HI in galaxies traces the fuel for future star formation and reveals effects of feedback on neutral gas. Using a statistically uniform, HI-selected sample 565 from ALFALFA H-alpha survey, we explore properties as function activity. provides R-band imaging volume-limited subset 21-cm survey. We identify eight starbursts based equivalent width six with enhanced relative to main sequence. Both non-starbursts have similar stellar mass ratios (MHI/M*), which suggests that is not depleting...
ABSTRACT The ALFALFA H α survey utilizes a large sample of i -selected galaxies from the to study star formation (SF) in local universe. contains 1555 with distances between ∼20 and ∼100 Mpc. We have obtained continuum-subtracted narrowband images broadband R for each galaxy, creating one largest homogeneous sets ever assembled. Our procedures were designed minimize uncertainties related calculation SF rate density (SFRD). galaxy we constructed is as close volume-limited possible, robust...
We present the Census of Local Universe (CLU) narrow-band survey to search for emission-line (\ha) galaxies. CLU-\ha~has imaged $\approx$3$\pi$ sky (26,470~deg$^2$) with 4 filters that probe a distance out 200~Mpc. have obtained spectroscopic follow-up galaxy candidates in 14 preliminary fields (101.6~deg$^2$) characterize limits and completeness survey. In these fields, CLU can identify emission lines down an \ha~flux limit $10^{-14}$~$\rm{erg~s^{-1}~cm^{-2}}$ at 90\% completeness, recovers...
We present H i spectral-line imaging of the extremely metal-poor galaxy DDO 68. This system has a nebular oxygen abundance only ∼3% Z☉, making it one most metal-deficient galaxies known in local volume. Surprisingly, 68 is relatively massive and luminous for its metal content, significant outlier mass–metallicity luminosity–metallicity relationships. The origin such low presents challenge models chemical evolution galaxies. One possible solution to this problem infall pristine neutral gas,...
We present kinematic analyses of the 12 galaxies in "Survey HI Extremely Low-mass Dwarfs" (SHIELD). use multi-configuration interferometric observations 21cm emission line from Karl G. Jansky Very Large Array (VLA) to produce image cubes at a variety spatial and spectral resolutions. Both two- three-dimensional fitting techniques are employed an attempt derive inclination-corrected rotation curves for each galaxy. In most cases, comparable magnitudes velocity dispersion projected result...
Detections of coalescing binary black holes by LIGO have opened a new window transient astronomy. With increasing sensitivity and participation the Virgo detector in Cascina, Italy, we expect to soon detect coalescence compact systems with one or more neutron stars. These are prime targets for electromagnetic follow-up gravitational wave triggers, which holds enormous promise rich science. However, hunting counterparts events is non-trivial task due sheer size error regions, could span...
Abstract We present the second catalog of serendipitously discovered compact extragalactic emission-line sources—H α Dots. These objects have been in searches moderately deep narrow-band images acquired for ALFALFA H project. In addition to cataloging 119 new Dots, we also follow-up spectral data full sample. spectra allow us confirm nature these as true objects, classify them terms activity type (star-forming or AGN), and identify emission line via which they were discovered. tabulate...
Abstract The first binary neutron star merger, GW170817, was accompanied by a radioactivity-powered optical/infrared transient called kilonova. To date, no compelling kilonova has been found in all-sky optical surveys, independently of short gamma-ray burst and gravitational-wave triggers. In this work, we searched the 23 months Zwicky Transient Facility (ZTF) data stream for candidate kilonovae form rapidly evolving transients. We combined ZTF alert queries with forced point-spread-function...
We present the fourth catalog of serendipitously discovered compact extragalactic emission-line sources -- H$\alpha$ Dots. A total 454 newly objects are included in current survey list. These have been detected searches moderately deep narrow-band images acquired for ALFALFA project (Van Sistine et al. 2016). The H-alpha Dots presented paper was derived from carried out using obtained with KPNO 2.1 m telescope. This results a substantially deeper sample compared to our previous lists, which...