P. W. Draper
Durham University
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Featured researches published by P. W. Draper.
The Astrophysical Journal | 2014
Armin Rest; D. Scolnic; Ryan J. Foley; M. Huber; Ryan Chornock; Gautham S. Narayan; John L. Tonry; Edo Berger; Alicia M. Soderberg; Christopher W. Stubbs; Adam G. Riess; Robert P. Kirshner; S. J. Smartt; Edward F. Schlafly; Steven A. Rodney; M. T. Botticella; D. Brout; Peter M. Challis; Ian Czekala; Maria Rebecca Drout; Michael J. Hudson; R. Kotak; C. Leibler; R. Lunnan; G. H. Marion; M. McCrum; D. Milisavljevic; Andrea Pastorello; Nathan Edward Sanders; K. W. Smith
We present griz P1 light curves of 146 spectroscopically confirmed Type Ia supernovae (SNe Ia; 0.03 < z < 0.65) discovered during the first 1.5 yr of the Pan-STARRS1 Medium Deep Survey. The Pan-STARRS1 natural photometric system is determined by a combination of on-site measurements of the instrument response function and observations of spectrophotometric standard stars. We find that the systematic uncertainties in the photometric system are currently 1.2% without accounting for the uncertainty in the Hubble Space Telescope Calspec definition of the AB system. A Hubble diagram is constructed with a subset of 113 out of 146 SNe Ia that pass our light curve quality cuts. The cosmological fit to 310 SNe Ia (113 PS1 SNe Ia + 222 light curves from 197 low-z SNe Ia), using only supernovae (SNe) and assuming a constant dark energy equation of state and flatness, yields . When combined with BAO+CMB(Planck)+H 0, the analysis yields and including all identified systematics. The value of w is inconsistent with the cosmological constant value of –1 at the 2.3σ level. Tension endures after removing either the baryon acoustic oscillation (BAO) or the H 0 constraint, though it is strongest when including the H 0 constraint. If we include WMAP9 cosmic microwave background (CMB) constraints instead of those from Planck, we find , which diminishes the discord to <2σ. We cannot conclude whether the tension with flat ΛCDM is a feature of dark energy, new physics, or a combination of chance and systematic errors. The full Pan-STARRS1 SN sample with ~three times as many SNe should provide more conclusive results.
The Astrophysical Journal | 2013
M. Fraser; M. R. Magee; R. Kotak; S. J. Smartt; K. W. Smith; J. Polshaw; Andrew J. Drake; T. Boles; Chien-Hsiu Lee; W. S. Burgett; K. C. Chambers; P. W. Draper; H. Flewelling; K. W. Hodapp; N. Kaiser; R.-P. Kudritzki; E. A. Magnier; P. A. Price; John L. Tonry; R. J. Wainscoat; C. Waters
Using imaging from the Pan-STARRS1 survey, we identify a precursor outburst at 287 and 170 days prior to the reported explosion of the purported Type IIn supernova (SN) 2011ht. In the Pan-STARRS data, a source coincident with SN 2011ht is detected exclusively in the z_(P1) and y_(P1)-bands. An absolute magnitude of M_z ≃ –11.8 suggests that this was an outburst of the progenitor star. Unfiltered, archival Catalina Real Time Transient Survey images also reveal a coincident source from at least 258 to 138 days before the main event. We suggest that the outburst is likely to be an intrinsically red eruption, although we cannot conclusively exclude a series of erratic outbursts which were observed only in the redder bands by chance. This is only the fourth detection of an outburst prior to a claimed SN, and lends credence to the possibility that many more interacting transients have pre-explosion outbursts, which have been missed by current surveys.
The Astrophysical Journal | 2015
B. P. Venemans; Eduardo Bañados; Roberto Decarli; E. P. Farina; F. Walter; K. C. Chambers; X. Fan; H.-W. Rix; Edward F. Schlafly; Richard G. McMahon; Robert A. Simcoe; D. Stern; W. S. Burgett; P. W. Draper; H. Flewelling; Klaus-Werner Hodapp; Nick Kaiser; E. A. Magnier; N. Metcalfe; Jeffrey S. Morgan; P. A. Price; John L. Tonry; C. Waters; Yusra AlSayyad; M. Banerji; S. S. Chen; E. Gonzalez-Solares; J. Greiner; Chiara Mazzucchelli; Ian D. McGreer
Luminous distant quasars are unique probes of the high redshift intergalactic medium (IGM) and of the growth of massive galaxies and black holes in the early universe. Absorption due to neutral Hydrogen in the IGM makes quasars beyond a redshift of z~6.5 very faint in the optical
The Astrophysical Journal | 2016
Edward F. Schlafly; A. M. Meisner; Amelia M. Stutz; Jouni Kainulainen; J. E. G. Peek; Kirill Tchernyshyov; H.-W. Rix; Douglas P. Finkbeiner; Kevin R. Covey; Gregory M. Green; Eric F. Bell; W. S. Burgett; K. C. Chambers; P. W. Draper; H. Flewelling; Klaus-Werner Hodapp; Nick Kaiser; E. A. Magnier; Nicolas F. Martin; N. Metcalfe; R. J. Wainscoat; C. Waters
z
Astrophysical Journal Supplement Series | 2016
Eduardo Bañados; B. P. Venemans; Roberto Decarli; E. P. Farina; Chiara Mazzucchelli; F. Walter; X. Fan; D. Stern; Edward F. Schlafly; K. C. Chambers; H.-W. Rix; Linhua Jiang; Ian D. McGreer; Robert A. Simcoe; Feige Wang; Jinyi Yang; Eric Morganson; G. De Rosa; J. Greiner; M. Baloković; W. S. Burgett; T. Cooper; P. W. Draper; H. Flewelling; Klaus-Werner Hodapp; Hyunsung David Jun; Nick Kaiser; R. P. Kudritzki; E. A. Magnier; N. Metcalfe
-band, thus locating quasars at higher redshifts require large surveys that are sensitive above 1 micron. We report the discovery of three new z>6.5 quasars, corresponding to an age of the universe of 6.5 quasars from 4 to 7. The quasars have redshifts of z=6.50, 6.52, and 6.66, and include the brightest z-dropout quasar reported to date, PSO J036.5078+03.0498 with M_1450=-27.4. We obtained near-infrared spectroscopy for the quasars and from the MgII line we estimate that the central black holes have masses between 5x10^8 and 4x10^9 M_sun, and are accreting close to the Eddington limit (L_Bol/L_Edd=0.13-1.2). We investigate the ionized regions around the quasars and find near zone radii of R_NZ=1.5-5.2 proper Mpc, confirming the trend of decreasing near zone sizes with increasing redshift found for quasars at 5.7<z<6.4. By combining R_NZ of the PS1 quasars with those of 5.7<z<7.1 quasars in the literature, we derive a luminosity corrected redshift evolution of R_NZ,corrected=(7.2+/-0.2)-(6.1+/-0.7)x(z-6) Mpc. However, the large spread in R_NZ in the new quasars implies a wide range in quasar ages and/or a large variation in the neutral Hydrogen fraction along different lines of sight.
The Astrophysical Journal | 2016
R. Lunnan; Ryan Chornock; Edo Berger; D. Milisavljevic; David O. Jones; Armin Rest; Wen-fai Fong; Claes Fransson; Raffaella Margutti; Maria Rebecca Drout; P. K. Blanchard; Peter M. Challis; P. S. Cowperthwaite; Ryan J. Foley; Robert P. Kirshner; Nidia I. Morrell; Adam G. Riess; Kathy Roth; D. Scolnic; S. J. Smartt; K. W. Smith; V. A. Villar; K. C. Chambers; P. W. Draper; M. Huber; N. Kaiser; R.-P. Kudritzki; E. A. Magnier; N. Metcalfe; C. Waters
The dust extinction curve is a critical component of many observational programs and an important diagnostic of the physics of the interstellar medium. Here we present new measurements of the dust extinction curve and its variation towards tens of thousands of stars, a hundred-fold larger sample than in existing detailed studies. We use data from the APOGEE spectroscopic survey in combination with ten-band photometry from Pan-STARRS1, 2MASS, and WISE. We find that the extinction curve in the optical through infrared is well characterized by a one-parameter family of curves described by R(V). The extinction curve is more uniform than suggested in past works, with sigma(R(V)) = 0.18, and with less than one percent of sight lines having R(V) > 4. Our data and analysis have revealed two new aspects of Galactic extinction: first, we find significant, wide-area variations in R(V) throughout the Galactic plane. These variations are on scales much larger than individual molecular clouds, indicating that R(V) variations must trace much more than just grain growth in dense molecular environments. Indeed, we find no correlation between R(V) and dust column density up to E(B-V) ~ 2. Second, we discover a strong relationship between R(V) and the far-infrared dust emissivity.
The Astrophysical Journal | 2015
William M. J. Best; Michael C. Liu; E. A. Magnier; Niall R. Deacon; Kimberly M. Aller; Joshua Redstone; W. S. Burgett; K. C. Chambers; P. W. Draper; H. Flewelling; Klaus-Werner Hodapp; Nick Kaiser; N. Metcalfe; John L. Tonry; R. J. Wainscoat; C. Waters
Luminous quasars at z > 5.6 can be studied in detail with the current generation of telescopes and provide us with unique information on the first gigayear of the universe. Thus far, these studies have been statistically limited by the number of quasars known at these redshifts. Such quasars are rare, and therefore, wide-field surveys are required to identify them, and multiwavelength data are required to separate them efficiently from their main contaminants, the far more numerous cool dwarfs. In this paper, we update and extend the selection for the z ~ 6 quasars presented in Banados et al. (2014) using the Pan-STARRS1 (PS1) survey. We present the PS1 distant quasar sample, which currently consists of 124 quasars in the redshift range 5.6 ≾ z ≾ 6.7 that satisfy our selection criteria. Of these quasars, 77 have been discovered with PS1, and 63 of them are newly identified in this paper. We present the composite spectra of the PS1 distant quasar sample. This sample spans a factor of ~20 in luminosity and shows a variety of emission line properties. The number of quasars at z > 5.6 presented in this work almost doubles the previously known quasars at these redshifts, marking a transition phase from studies of individual sources to statistical studies of the high-redshift quasar population, which was impossible with earlier, smaller samples.
The Astrophysical Journal | 2015
D. Scolnic; Stefano Casertano; Adam G. Riess; Armin Rest; Edward F. Schlafly; Ryan J. Foley; Douglas P. Finkbeiner; C. Tang; W. S. Burgett; K. C. Chambers; P. W. Draper; H. Flewelling; Klaus-Werner Hodapp; M. E. Huber; Nick Kaiser; R. P. Kudritzki; E. A. Magnier; N. Metcalfe; Christopher W. Stubbs
We present photometry and spectroscopy of PS1-14bj, a hydrogen-poor superluminous supernova (SLSN) at redshift
The Astrophysical Journal | 2018
R. Lunnan; Ryan Chornock; Edo Berger; David O. Jones; Armin Rest; Ian Czekala; Jason A. Dittmann; M. R. Drout; Ryan J. Foley; W. Fong; Robert P. Kirshner; Tanmoy Laskar; C. Leibler; Raffaella Margutti; D. Milisavljevic; Gautham S. Narayan; Y.-C. Pan; Adam G. Riess; Kathy Roth; Nathan Edward Sanders; D. Scolnic; S. J. Smartt; K. W. Smith; K. C. Chambers; P. W. Draper; H. Flewelling; M. Huber; N. Kaiser; R.-P. Kudritzki; E. A. Magnier
z=0.5215
Monthly Notices of the Royal Astronomical Society | 2015
J. Liu; C. Hennig; S. Desai; B. Hoyle; J. Koppenhoefer; J. J. Mohr; Kerstin Paech; W. S. Burgett; K. C. Chambers; Shaun Cole; P. W. Draper; N. Kaiser; N. Metcalfe; Jeffrey S. Morgan; P. A. Price; Christopher W. Stubbs; John L. Tonry; R. J. Wainscoat; C. Waters
discovered in the last months of the Pan-STARRS1 Medium Deep Survey. PS1-14bj stands out by its extremely slow evolution, with an observed rise of