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Monthly Notices of the Royal Astronomical Society | 2010

A high-velocity narrow absorption line outflow in the quasar J212329.46 − 005052.9

Fred Hamann; Nissim Kanekar; Jason X. Prochaska; Michael T. Murphy; Sara L. Ellison; A. L. Malec; Nikola Milutinovic; W.M.G. Ubachs

We report on the discovery of a high-velocity narrow absorption line outflow in the redshift 2.3 quasar J212329.46-005052.9.Five distinct outflow systems are detected with velocity shifts from 9710 to 14,050 km s 1 and Civ ��1548,1551 line widths of FWHM � 62 to 164 km s 1 . This outflow is remarkable for having high speeds and a degree of ionization similar to broad absorption line (BAL) flows, but line widths roughly 100 times narrower than BALs and no apparent X-ray absorption. This is also, to our knowledge, the highest-velocity narrow absorption line system confirmed to be in a quasar outflow by all three indicators of line variability, smooth super-thermal line profiles and doublet ratios that require partial covering of the quasar continuum source. All five systems have stronger absorption in Ovi ��1032,1038 than Civ with no lower ionization metal lines detected. Their line variabilities also appear coordinated, with each system showing larger changes in Civ than Ovi and line strength variations accompanied by nearly commensurate changes in the absorber covering fractions. The metallicity is approximately twice solar. These data require five distinct outflow structures with similar kinematics, physical conditions and characteristic sizes of order 0.01-0.02 pc (based on partial covering). The coordinated line variations, occurring on time scales 60.63 yr (quasar frame), are best explained by global changes in the outflow ionization caused by changes in the quasar’s ionizing flux. An upper limit on the acceleration, .3 km s 1 yr 1 , is consistent with blobs of gas that are gravitationally unbound and coasting freely &5 pc from the central black hole. Additional constraints from the variability time indicate that the full range of plausible distances is 5 . R . 1100 pc. However, if these small absorbing structures were created in the inner flow, they should be near the �5 pc minimum radius because they can travel just a few pc before dissipating (without external confinement). An apparent double line-lock in Civ suggests that the flow was radiatively accelerated and its present trajectory is within �16 o of the radial (line-ofsight) direction. The absence of strong X-ray absorption shows that radiative shielding in the far-UV and X-rays is not needed to maintain moderate BAL-like ionizations and therefore, apparently, it is not needed to facilitate the radiative acceleration to high speeds. We argue that the ionization is moderated, instead, by high gas densities in small outflow sub-structures. Finally, we estimate that the kinetic energy yield from this outflow is at least two orders of magnitude too low to be important for feedback to the host galaxy’s evolution.


Monthly Notices of the Royal Astronomical Society | 2010

Keck Telescope Constraint on Cosmological Variation of the Proton-to-Electron Mass Ratio

A. L. Malec; R. Buning; Michael T. Murphy; Nikola Milutinovic; Sara L. Ellison; Jason X. Prochaska; L. Kaper; Jason Tumlinson; R. F. Carswell; W.M.G. Ubachs

Molecular transitions recently discovered at redshift z(abs) = 2.059 towards the bright background quasar J2123-0050 are analysed to limit cosmological variation in the proton-to-electron mass ratio, mu equivalent to m(p)/m(e). Observed with the Keck telescope, the optical echelle spectrum has the highest resolving power and largest number (86) of H-2 transitions in such analyses so far. Also, (seven) HD transitions are used for the first time to constrain mu-variation. These factors, and an analysis employing the fewest possible free parameters, strongly constrain mus relative deviation from the current laboratory value: delta mu/mu = (+5.6 +/- 5.5(stat) +/- 2.9(sys)) x 10-6, indicating an insignificantly larger mu in the absorber. This is the first Keck result to complement recent null constraints from three systems at z(abs) > 2.5 observed with the Very Large Telescope. The main possible systematic errors stem from wavelength calibration uncertainties. In particular, distortions in the wavelength solution on echelle order scales are estimated to contribute approximately half the total systematic error component, but our estimate is model dependent and may therefore under or overestimate the real effect, if present. To assist future mu-variation analyses of this kind, and other astrophysical studies of H-2 in general, we provide a compilation of the most precise laboratory wavelengths and calculated parameters important for absorption-line work with H-2 transitions redwards of the hydrogen Lyman limit.


The Astrophysical Journal | 2011

The Transitional Stripped-Envelope SN 2008ax: Spectral Evolution and Evidence for Large Asphericity

Ryan Chornock; Alexei V. Filippenko; Weidong Li; G. H. Marion; Ryan J. Foley; Maryam Modjaz; Marc Rafelski; George D. Becker; W. H. de Vries; Peter Marcus Garnavich; Regina A. Jorgenson; David K. Lynch; A. L. Malec; Edward C. Moran; Michael T. Murphy; Richard J. Rudy; Ray W. Russell; Jeffrey M. Silverman; Thea N. Steele; Alan N. Stockton; Arthur M. Wolfe; Charles E. Woodward

Supernova (SN) 2008ax in NGC 4490 was discovered within hours after shock breakout, presenting the rare opportunity to study a core-collapse SN beginning with the initial envelope-cooling phase immediately following shock breakout. We present an extensive sequence of optical and near-infrared spectra, as well as three epochs of optical spectropolarimetry. Our initial spectra, taken two days after shock breakout, are dominated by hydrogen Balmer lines at high velocity. However, by maximum light, He I lines dominated the optical and near-infrared spectra, which closely resembled those of normal Type Ib supernovae (SNe Ib) such as SN 1999ex. This spectroscopic transition defines Type IIb SNe, but the strong similarity of SN 2008ax to normal SNe Ib beginning near maximum light, including an absorption feature near 6270 A due to Hα at high velocities, suggests that many objects classified as SNe Ib in the literature may have ejected similar amounts of hydrogen as SN 2008ax, roughly a few × 0.01 M ☉. Only the unusually early discovery of SN 2008ax allowed us to observe the spectroscopic signatures of the hydrogen-rich outer ejecta. Early-time spectropolarimetry (six and nine days after shock breakout) revealed strong line polarization modulations of 3.4% across Hα, indicating the presence of large asphericities in the outer ejecta and possibly that the spectrum of SN 2008ax could be dependent on the viewing angle. After removal of interstellar polarization, the continuum shares a common polarization angle with the hydrogen, helium, and oxygen lines, while the calcium and iron absorptions are oriented at different angles. This is clear evidence of deviations from axisymmetry even in the outer ejecta. Intrinsic continuum polarization of 0.64% only nine days after shock breakout shows that the outer layers of the ejecta were quite aspherical. A single epoch of late-time spectropolarimetry as well as the shapes of the nebular line profiles demonstrate that asphericities extended from the outermost layers all the way down to the center of this core-collapse SN. SN 2008ax may in some ways be an extragalactic analog of the explosion giving rise to Cassiopeia A, which has recently been determined to be a remnant of an SN IIb.


Physical Review Letters | 2011

First constraint on cosmological variation of the proton-to-electron mass ratio from two independent telescopes

F. van Weerdenburg; Michael T. Murphy; A. L. Malec; L. Kaper; W.M.G. Ubachs

A high signal-to-noise spectrum covering the largest number of hydrogen lines (90 H(2) lines and 6 HD lines) in a high-redshift object was analyzed from an observation along the sight line to the bright quasar source J2123-005 with the Ultraviolet and Visual Echelle Spectrograph on the European Southern Observatory Very Large Telescope (Paranal, Chile). This delivers a constraint on a possible variation of the proton-to-electron mass ratio of Δμ/μ=(8.5 ± 3.6(stat) ± 2.2(syst))×10(-6) at redshift z(abs) = 2.059, which agrees well with a recently published result on the same system observed at the Keck telescope yielding Δμ/μ=(5.6 ± 5.5(stat) ± 2.9(syst))×10(-6). Both analyses used the same robust absorption line fitting procedures with detailed consideration of systematic errors.


The Astrophysical Journal | 2010

Cosmological Concordance or Chemical Coincidence? Deuterated Molecular Hydrogen Abundances at High Redshift

Jason Tumlinson; A. L. Malec; R. F. Carswell; Michael T. Murphy; R. Buning; Nikola Milutinovic; Sara L. Ellison; Jason X. Prochaska; Regina A. Jorgenson; W.M.G. Ubachs; Arthur M. Wolfe

We report two detections of deuterated molecular hydrogen (HD) in QSO absorption-line systems at z>2. Toward J2123–0500, we find N(HD) =13.84 ± 0.2 for a sub-Damped Lyman Alpha system (DLA) with metallicity 0.5Z ☉ and N(H2) = 17.64 ± 0.15 at z = 2.0594. Toward FJ0812+32, we find N(HD) =15.38 ± 0.3 for a solar-metallicity DLA with N(H2) = 19.88 ± 0.2 at z = 2.6265. These systems have ratios of HD to H2 above that observed in dense clouds within the Milky Way disk and apparently consistent with a simple conversion from the cosmological ratio of D/H. These ratios are not readily explained by any available model of HD chemistry, and there are no obvious trends with metallicity or molecular content. Taken together, these two systems and the two published z>2 HD-bearing DLAs indicate that HD is either less effectively dissociated or more efficiently produced in high-redshift interstellar gas, even at low molecular fraction and/or solar metallicity. It is puzzling that such diverse systems should show such consistent HD/H2 ratios. Without clear knowledge of all the aspects of HD chemistry that may help determine the ratio HD/H2, we conclude that these systems are potentially more revealing of gas chemistry than of D/H itself and that it is premature to use such systems to constrain D/H at high redshift.


Monthly Notices of the Royal Astronomical Society | 2016

Precise limits on cosmological variability of the fine-structure constant with zinc and chromium quasar absorption lines

Michael T. Murphy; A. L. Malec; J. Xavier Prochaska

The strongest transitions of Zn and CrII are the most sensitive to relative variations in the fine-structure constant (


arXiv: Cosmology and Nongalactic Astrophysics | 2009

New limit on a varying proton-to-electron mass ratio from high resolution optical quasar spectra

A. L. Malec; R. Buning; Michael T. Murphy; Nikola Milutinovic; Sara L. Ellison; J. Xavier Prochaska; L. Kaper; Jason Tumlinson; R. F. Carswell; W.M.G. Ubachs

\Delta\alpha/\alpha


Monthly Notices of the Royal Astronomical Society | 2012

Three-dimensional shapelets and an automated classification scheme for dark matter haloes

Christopher J. Fluke; A. L. Malec; P. D. Lasky; Benjamin R. Barsdell

) among the transitions commonly observed in quasar absorption spectra. They also lie within just 40A of each other (rest frame), so they are resistant to the main systematic error affecting most previous measurements of


Mem.Soc.Ast.It. | 2010

New limit on a varying proton-to-electron mass ratio from high-resolution optical quasar spectra

A. L. Malec; Nikola Milutinovic; R. Buning; Michael T. Murphy; Sara L. Ellison; W.M.G. Ubachs; Jason X. Prochaska; R. F. Carswell; Jason Tumlinson; L. Kaper

\Delta\alpha/\alpha


Archive | 2016

Quasar spectra and Zn/CrII absorption profile fits for limiting fine-structure constant variability

Michael T. Murphy; A. L. Malec; J. Xavier Prochaska

: long-range distortions of the wavelength calibration. While Zn and CrII absorption is normally very weak in quasar spectra, we obtained high signal-to-noise, high-resolution echelle spectra from the Keck and Very Large Telescopes of 9 rare systems where it is strong enough to constrain

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Michael T. Murphy

Swinburne University of Technology

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Jason Tumlinson

Space Telescope Science Institute

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R. Buning

VU University Amsterdam

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L. Kaper

University of Amsterdam

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