Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 14 of 14

Full-Text Articles in Physical Sciences and Mathematics

Intensities, Broadening And Narrowing Parameters In The Ν3 Band Of Methane, Et-Touhami Es-Sebbar, Aamir Farooq Aug 2014

Intensities, Broadening And Narrowing Parameters In The Ν3 Band Of Methane, Et-Touhami Es-Sebbar, Aamir Farooq

Dr. Et-touhami Es-sebbar

The P-branch of methane׳s ν3 band is probed to carry out an extensive study of the 2905–2908 cm−1 infrared spectral region. Absolute line intensities as well as N2-, O2-, H2-, He-, Ar- and CO2-broadening coefficients are determined for nine transitions at room temperature. Narrowing parameters due to the Dicke effect have also been investigated. A narrow emission line-width (~0.0001 cm−1) difference-frequency-generation (DFG) laser system is used as the tunable light source. To retrieve the CH4 spectroscopic parameters, Voigt and Galatry profiles were used to simulate the measured line shape of the individual transitions.


Evidence Of A Mira-Like Tail And Bow Shock About The Semi-Regular Variable V Cvn From Four Decades Of Polarization Measurements., Hilding R. Neilson, Richard Ignace, Beverly J. Smith, Gary Henson, Alyssa M. Adams Aug 2014

Evidence Of A Mira-Like Tail And Bow Shock About The Semi-Regular Variable V Cvn From Four Decades Of Polarization Measurements., Hilding R. Neilson, Richard Ignace, Beverly J. Smith, Gary Henson, Alyssa M. Adams

Richard Ignace

Polarization is a powerful tool for understanding stellar atmospheres and circumstellar environments. Mira and semi-regular variable stars have been observed for decades and some are known to be polarimetrically variable, however, the semi-regular variable V Canes Venatici displays an unusually large, unexplained amount of polarization. We present ten years of optical polarization observations obtained with the HPOL instrument, supplemented by published observations spanning a total interval of about forty years for V CVn. We find that V CVn shows large polarization variations ranging from 1 - 6%. We also find that for the past forty years the position angle measured …


Inferring The Global Cosmic Dust Influx To The Earth’S Atmosphere From Lidar Observations Of The Vertical Flux Of Mesospheric Na, Chester S. Gardner, Alan Z. Liu, Dan Marsh, Wuhu Feng, John Plane Aug 2014

Inferring The Global Cosmic Dust Influx To The Earth’S Atmosphere From Lidar Observations Of The Vertical Flux Of Mesospheric Na, Chester S. Gardner, Alan Z. Liu, Dan Marsh, Wuhu Feng, John Plane

Alan Z Liu

Estimates of the global influx of cosmic dust are highly uncertain, ranging from 0.4110 t/d. All
meteoric debris that enters the Earths atmosphere is eventually transported to the surface. The downward
fluxes of meteoric metals like mesospheric Na and Fe, in the region below where they are vaporized and
where the majority of these species are still in atomic form, are equal to their meteoric ablation influxes,
which in turn, are proportional to the total cosmic dust influx. Doppler lidar measurements of mesospheric Na
fluxes made throughout the …


C/2013 R1 (Lovejoy) At Ir Wavelengths And The Variability Of Co Abundances Among Oort Cloud Comets, L. Paganini, M. J. Mumma, G. L. Villanueva, J. V. Keane, G. A. Blake, B. P. Bonev, M. A. Disanti, E. L. Gibb, K. J. Meech Aug 2014

C/2013 R1 (Lovejoy) At Ir Wavelengths And The Variability Of Co Abundances Among Oort Cloud Comets, L. Paganini, M. J. Mumma, G. L. Villanueva, J. V. Keane, G. A. Blake, B. P. Bonev, M. A. Disanti, E. L. Gibb, K. J. Meech

Erika Gibb

We report production rates, rotational temperatures, and related parameters for gases in C/2013 R1 (Lovejoy) using the Near InfraRed SPECtrometer at the Keck Observatory, on six UT dates spanning heliocentric distances (Rh ) that decreased from 1.35 AU to 1.16 AU (pre-perihelion). We quantified nine gaseous species (H2O, OH*, CO, CH4, HCN, C2H6, CH3OH, NH3, and NH2) and obtained upper limits for two others (C2H2 and H2CO). Compared with organics-normal comets, our results reveal highly enriched CO, (at most) slightly enriched CH3OH, C2H6, and HCN, and CH4 consistent with "normal", yet depleted, NH3, C2H2, and H2CO. Rotational temperatures increased from …


The Redshift Search Receiver 3 Mm Wavelength Spectra Of 10 Galaxies, Ronald L. Snell, Gopal Narayanan, Min Yun, M Heyer, A Chung, William M. Irvine, Nr Erickson, G Liu Aug 2014

The Redshift Search Receiver 3 Mm Wavelength Spectra Of 10 Galaxies, Ronald L. Snell, Gopal Narayanan, Min Yun, M Heyer, A Chung, William M. Irvine, Nr Erickson, G Liu

William M. Irvine

The 3 mm wavelength spectra of 10 galaxies have been obtained at the Five College Radio Astronomy Observatory using a new, very broadband receiver and spectrometer, called the Redshift Search Receiver (RSR). The RSR has an instantaneous bandwidth of 37 GHz covering frequencies from 74 to 111 GHz and has a spectral resolution of 31 MHz (~100 km s–1). During tests of the RSR on the FCRAO 14 m telescope the complete 3 mm spectra of the central regions of NGC 253, Maffei 2, NGC1068, IC 342, M82, NGC 3079, NGC 3690, NGC 4258, Arp 220, and NGC 6240 were …


The Final Journey Of The Saturn V, Andrew R. Thomas, Paul N. Thomarios Jul 2014

The Final Journey Of The Saturn V, Andrew R. Thomas, Paul N. Thomarios

Andrew R. Thomas

The Saturn V rocket carried men to the moon, and its history reflects the US space program's rise, success, and demise. In 1961, John F. Kennedy challenged America to put a man on the moon and win the space race. Neil Armstrong set foot on the moon in 1969 in the culmination of a concerted scientific and technological effort. A little over a decade later, the Saturn rocket was tossed aside to rot in a field near the Kennedy Space Center in Florida. The rocket's carcass became the home to flora and fauna. Like the space program itself, the rocket …


Discovery Of X-Ray Pulsations From A Massive Star., Lidia M. Oskinova, Yael Nazé, Helge Todt, David P. Huenemoerder, Richard Ignace, Swetlana Hubrig, Wolf-Rainer Hamann Jun 2014

Discovery Of X-Ray Pulsations From A Massive Star., Lidia M. Oskinova, Yael Nazé, Helge Todt, David P. Huenemoerder, Richard Ignace, Swetlana Hubrig, Wolf-Rainer Hamann

Richard Ignace

X-ray emission from stars much more massive than the Sun was discovered only 35 years ago. Such stars drive fast stellar winds where shocks can develop, and it is commonly assumed that the X-rays emerge from the shock-heated plasma. Many massive stars additionally pulsate. However, hitherto it was neither theoretically predicted nor observed that these pulsations would affect their X-ray emission. All X-ray pulsars known so far are associated with degenerate objects, either neutron stars or white dwarfs. Here we report the discovery of pulsating X-rays from a non-degenerate object, the massive B-type star ξ1 CMa. This star is …


Faraday Rotation Effects For Diagnosing Magnetism In Bubble Environments., Richard Ignace May 2014

Faraday Rotation Effects For Diagnosing Magnetism In Bubble Environments., Richard Ignace

Richard Ignace

Faraday rotation is a process by which the position angle (PA) of background linearly polarized light is rotated when passing through an ionized and magnetized medium. The effect is sensitive to the line-of-sight magnetic field in conjunction with the electron density. This contribution highlights diagnostic possibilities of inferring the magnetic field (or absence thereof) in and around wind-blown bubbles from the Faraday effect. Three cases are described as illustrations: a stellar toroidal magnetic field, a shocked interstellar magnetic field, and an interstellar magnetic field within an ionized bubble.


Gravitational Wave Astrophysics With Compact Binary Systems, Eric Addison Apr 2014

Gravitational Wave Astrophysics With Compact Binary Systems, Eric Addison

Eric Addison

Gravitational waves are ripples in the fabric of spacetime that convey information about
changing gravitational fields. Large-scale detection projects are currently in operation, and
more advanced detectors are being designed and built. Though we have yet to make a
direct detection of a gravitational wave signal, upgrades to current detectors are expected
to bring the first detections within the next year or two.

Gravitational waves will bring us information about astrophysical phenomena that is
complementary to the information gained from photon-based observations (e.g., telescopes
and radio receivers). One of the primary sources of gravitational waves are binary systems:
two massive …


Soliciting The Universe, A Prose/Poem 4/1/2014, Charles Kay Smith Mar 2014

Soliciting The Universe, A Prose/Poem 4/1/2014, Charles Kay Smith

Charles Kay Smith

Why it may not be wise to radio our presence into outer space, but why humans are compelled by their neotenic proclivities to be curious and to solicit attention.


The Allen Telescope Array Search For Electrostatic Discharges On Mars, Marin M. Anderson, Andrew P.V. Siemion, William C. Barott, Geoffery C. Bower, Gregory T. Delory, Imke De Pater, Dan Werthimer Mar 2014

The Allen Telescope Array Search For Electrostatic Discharges On Mars, Marin M. Anderson, Andrew P.V. Siemion, William C. Barott, Geoffery C. Bower, Gregory T. Delory, Imke De Pater, Dan Werthimer

William Barott

The Allen Telescope Array was used to monitor Mars between 2010 March 9 and June 2, over a total of approximately 30 hr, for radio emission indicative of electrostatic discharge. The search was motivated by the report from Ruf et al. of the detection of non-thermal microwave radiation from Mars characterized by peaks in the power spectrum of the kurtosis, or kurtstrum, at 10 Hz, coinciding with a large dust storm event on 2006 June 8. For these observations, we developed a wideband signal processor at the Center for Astronomy Signal Processing and Electronics Research. This 1024 channel spectrometer calculates …


Convection, Granulation, And Period Jitter In Classical Cepheids., Hilding R. Neilson, Richard Ignace Feb 2014

Convection, Granulation, And Period Jitter In Classical Cepheids., Hilding R. Neilson, Richard Ignace

Richard Ignace

Analyses of recent observations of the sole classical Cepheid in the Kepler field, V1154 Cygni, found random changes of about 30 min in the pulsation period. These period changes challenge standard theories of pulsation and evolution because the period change is non-secular, and explaining this period jitter is necessary for understanding stellar evolution and the role of Cepheids as precise standard candles. We suggest that convection and convective hot spots can explain the observed period jitter. Convective hot spots alter the timing of flux maximum and minimum in the Cepheid light curve, hence change the measured pulsation period. We present …


Transverse And Longitudinal Mass Moving In The Inertial Frame Of Reference, Vildyan Yanbikov Dec 2013

Transverse And Longitudinal Mass Moving In The Inertial Frame Of Reference, Vildyan Yanbikov

Vildyan Yanbikov

Based on the speed of the spread of vector interaction in a moving inertial frame of reference. A calculation of the transversal and longitudinal mass of elementary particles.


Continuum Polarization In Circumstellar Media, Richard Ignace Dec 2013

Continuum Polarization In Circumstellar Media, Richard Ignace

Richard Ignace

See http://www.asu.cas.cz/~wg2prague/