James D. Neill
A5089039466- Gamma-ray bursts and supernovae
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Galaxies: Formation, Evolution, Phenomena
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Astronomical Observations and Instrumentation
- Pulsars and Gravitational Waves Research
- Power Systems and Technologies
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Optical Systems and Laser Technology
- Solar and Space Plasma Dynamics
- Adaptive optics and wavefront sensing
- Neutrino Physics Research
- Smart Grid and Power Systems
- Particle Accelerators and Free-Electron Lasers
- Calibration and Measurement Techniques
- History and Developments in Astronomy
- CCD and CMOS Imaging Sensors
- Radio Astronomy Observations and Technology
- Atmospheric Ozone and Climate
- Planetary Science and Exploration
- Cosmology and Gravitation Theories
- Photocathodes and Microchannel Plates
California Institute of Technology
2015-2024
Carnegie Observatories
2020
Carnegie Institution for Science
2020
Schlumberger (British Virgin Islands)
2019
Quest Diagnostics (United States)
2012
University of Victoria
2005-2008
University of Oxford
2007
Centre National de la Recherche Scientifique
2007
University of Toronto
2007
Institut National de Physique Nucléaire et de Physique des Particules
2007
We present distance measurements to 71 high redshift type Ia supernovae discovered during the first year of 5-year Supernova Legacy Survey (SNLS). These events were detected and their multi-color light-curves measured using MegaPrime/MegaCam instrument at Canada-France-Hawaii Telescope (CFHT), by repeatedly imaging four one-square degree fields in bands, as part CFHT (CFHTLS). Follow-up spectroscopy was performed VLT, Gemini Keck telescopes confirm nature measure redshift. With this data...
We combine high redshift Type Ia supernovae from the first 3 years of Supernova Legacy Survey (SNLS) with other supernova (SN) samples, primarily at lower redshifts, to form a high-quality joint sample 472 SNe (123 low-$z$, 93 SDSS, 242 SNLS, and 14 {\it Hubble Space Telescope}). SN data alone require cosmic acceleration >99.9% confidence, including systematic effects. For dark energy equation state parameter (assumed constant out least $z=1.4$) in flat universe, we find $w =...
We present observational constraints on the nature of dark energy using Supernova Legacy Survey three-year sample (SNLS3) Guy et al. and Conley use 472 Type Ia supernovae (SNe Ia) in this sample, accounting for recently discovered correlations between SN luminosity host galaxy properties, include effects all identified systematic uncertainties directly cosmological fits. Combining SNLS3 data with full WMAP7 power spectrum, Sloan Digital Sky luminous red a prior Hubble constant H0 from SHOES,...
(Abridged) Precision cosmology with Type Ia supernovae (SNe Ia) makes use of the fact that SN luminosities depend on their light-curve shapes and colours. Using Supernova Legacy Survey (SNLS) other data, we show there is an additional dependence global characteristics host galaxies: events same shape colour are, average, 0.08mag (~4.0sigma) brighter in massive galaxies (presumably metal-rich) low specific star-formation rates (sSFR). SNe a sSFR also have smaller slope ("beta") between...
(ABRIDGED) We show that Type Ia supernovae (SNe Ia) are formed within both very young and old stellar populations, with observed rates depend on the mass mean star-formation (SFRs) of their host galaxies. Models where SN rate depends solely galaxy ruled out 99% confidence. Our analysis is based 100 spectroscopically-confirmed SNe Ia, plus 24 photometrically-classified events, all from Supernova Legacy Survey (SNLS) distributed over 0.2
The Wide-field Infrared Survey Explorer (WISE) mapped the entire sky at mid-infrared wavelengths 3.4, 4.6, 12 and 22 microns. mission was primarily designed to extract point sources, leaving resolved extended sources unexplored. We have begun a dedicated WISE Enhanced Resolution Galaxy Atlas (WERGA) project fully characterize large, nearby galaxies produce legacy image atlas source catalogue. Here we demonstrate first results of for sample 17 galaxies, chosen be large angular size, diverse...
Wide-field optical surveys have begun to uncover large samples of fast (trise ≲ 5 d), luminous (Mpeak < −18), blue transients. While commonly attributed the breakout a supernova shock into dense wind, great distances transients this class found so far hampered detailed investigation their properties. We present photometry and spectroscopy from comprehensive worldwide campaign observe AT 2018cow (ATLAS 18qqn), first fast-luminous transient be in real time at low redshift. Our spectra (<2 days...
Abstract We present a public catalog of transients from the Zwicky Transient Facility (ZTF) Bright Survey, magnitude-limited ( m < 19 mag in either g or r filter) survey for extragalactic ZTF stream. introduce cuts on coverage, sky visibility around peak light, and other properties unconnected to nature transient, show that resulting statistical sample is spectroscopically 97% complete at <18 mag, 93% <18.5 75% <19 mag. summarize fundamental this population, identifying distinct...
Abstract Narrow transient emission lines (flash-ionization features) in early supernova (SN) spectra trace the presence of circumstellar material (CSM) around massive progenitor stars core-collapse SNe. The disappear within days after SN explosion, suggesting that this is spatially confined, and originates from enhanced mass loss shortly (months to a few years) prior explosion. We performed systematic survey H-rich (Type II) SNe discovered less than 2 explosion during first phase Zwicky...
view Abstract Citations (306) References (62) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Planetary Nebulae as Standard Candles. II. The Calibration in M31 and Its Companions Ciardullo, Robin ; Jacoby, George H. Ford, Holland C. Neill, James D. We present the results of a planetary nebula survey M31's bulge performed with Kitt Peak No. 1 0.9 m telescope on-band off-band λ5007 filters. detected total 429 nebulae (PNs), which 104 are members statistically...
We present new techniques for improving the efficiency of supernova (SN) classification at high redshift using 64 candidates observed Gemini North and South during first year Supernova Legacy Survey (SNLS). The SNLS is an ongoing 5 project with goal measuring equation state dark energy by discovering following over 700 high-redshift SNe Ia data from Canada-France-Hawaii Telescope Survey. achieve improvement in SN spectroscopic confirmation rate: 71% are now confirmed as Ia, compared to 54%...
We present the Pan-STARRS1 discovery of long-lived and blue transient PS1-11af, which was also detected by Galaxy Evolution Explorer with coordinated observations in near-ultraviolet (NUV) band. PS1-11af is associated nucleus an early type galaxy at redshift z = 0.4046 that exhibits no evidence for star formation or active galactic activity. Four epochs spectroscopy reveal a pair broad absorption features UV on otherwise featureless spectra. Despite superficial similarity these to P-Cygni...
Millisecond duration bright radio pulses at 1.4-GHz with high dispersion measures (DM) were reported by Lorimer et al., Keane and Thornton al. Their all-sky rate is $\approx 10^4$/day above $\sim$1 Jy. Related events are "Perytons" -- similar pulsed, dispersed sources, but most certainly local. Suggested models of fast bursts (FRBs) can originate in the Earth's atmosphere, stellar coronae, other galaxies, even cosmological distances. Using physically motivated assumptions combined observed...
We present the discovery of two ultra-luminous supernovae (SNe) at z ~ 0.9 with Pan-STARRS1 Medium-Deep Survey. These SNe, PS1-10ky and PS1-10awh, are amongst most luminous SNe ever discovered, comparable to unusual transients SN 2005ap SCP 06F6. Like 06F6, they show characteristic high luminosities (M_bol -22.5 mag), blue spectra a few broad absorption lines, no evidence for H or He. have constructed full multi-color light curve sensitive peak spectral energy distribution in rest-frame...
Type-IIn supernovae (SNe), which are characterized by strong interaction of their ejecta with the surrounding circumstellar matter (CSM), provide a unique opportunity to study mass-loss history massive stars shortly before explosive death. We present discovery and follow-up observations Type IIn SN, PTF 09uj, detected Palomar Transient Factory (PTF). Serendipitous GALEX at ultraviolet (UV) wavelengths rise SN light curve prior discovery. The UV rose fast, time scale few days, absolute AB...
We use GALEX ultraviolet (UV) and optical integrated photometry of the hosts 17 luminous supernovae (LSNe, having peak MV < −21) compare them to a sample 26, 000 galaxies from cross-match between SDSS DR4 spectral catalog interim release 1.1. place LSN on galaxy NUV − r versus Mr color–magnitude diagram (CMD) with larger illustrate how extreme they are. The appear favor low-density regions CMD falling blue edge cloud toward low-luminosity end. From UV-optical photometry, we estimate star...
We investigate the nature of star formation law at low gas surface densities using a sample 19 brightness (LSB) galaxies with existing H i maps in literature, UV imaging from Galaxy Evolution Explorer satellite, and optical images Sloan Digital Sky Survey. All LSB have (NUV − r) colors similar to those for higher star-forming luminosity indicating that their average histories are not very different. Based upon four both far-infrared (FIR) data, we find FIR/UV ratios significantly less than...
This paper involves a data release of the observational campaign: Cosmicflows with Spitzer (CFS). Surface photometry 1270 galaxies constituting survey is presented. An additional ∼400 from various other surveys are also analysed. CFS complements Survey Stellar Structure in Galaxies, that provides for an 2352 galaxies, by extending observations to low galactic latitudes (|b| < 30°). Among these calibrators, selected K band, Tully–Fisher relation. The addition new calibrators demonstrates...
Abstract The Zwicky Transient Facility (ZTF) is performing a three-day cadence survey of the visible northern sky (∼3 π ) with newly found transient candidates announced via public alerts. ZTF Bright Survey (BTS) large spectroscopic campaign to complement photometric survey. BTS endeavors spectroscopically classify all extragalactic transients m peak ≤ 18.5 mag in either g or r filters, and publicly announce said classifications. discoveries are predominantly supernovae (SNe), making this...
We present a radio-quiet quasar at z=0.237 discovered "turning on" by the intermediate Palomar Transient Factory (iPTF). The transient, iPTF 16bco, was detected in nucleus of galaxy with an archival SDSS spectrum weak narrow-line emission characteristic low-ionization line region (LINER). Our follow-up spectra show dramatic appearance broad Balmer lines and power-law continuum luminous (L_bol~10^45 erg/s) type 1 12 years later. photometric monitoring PTF from 2009-2012, serendipitous X-ray...
Current time domain facilities are discovering hundreds of new galactic and extra-galactic transients every week. Classifying the ever-increasing number is challenging, yet crucial to further our understanding their nature, discover classes, or ensuring sample purity, for instance, Supernova Ia cosmology. The Zwicky Transient Facility one example such a survey. In addition, it has dedicated very-low resolution spectrograph, SEDMachine, operating on Palomar 60-inch telescope. This...