19 research outputs found
High time resolution studies of binary x ray pulsars
This report covers the period September 1, 1992 through August 1, 1993 for NASA grant NAG 5-1260 through the Astrophysics Data Program (ADP), for the project 'High Time Resolution Studies of Binary X-ray Pulsars'. During the past 11 months, we have concentrated on scientific analysis of the data, and have had to reanalyze several data sets, due to a newly discovered error in the unpacking of the count rate data. This error has now been corrected, but may have caused us to miss some scientific results, so we have gone back and reanalyzed the affected data sets, as well as continuing our analysis of other objects
ROSAT observations of the binary Be-star and radio pulsar PSR1259-63
This report discusses the ROSAT guest investigator program for the project 'ROSAT Observations of the Binary Be-star/Radio Pulsar PSR1259-63'. Work was done on this, and a previous grant entitled ROSAT Observations of MXB 1659-29 and EXO 0748-676 during this reporting period. A theory paper was written which proposes a new model to explain the X-ray emission from PSR 1259-63, in which the effects of accretion onto the magnetosphere of the neutron star, rather than onto the light cylinder which is conventionally assumed, is calculated. This approach works well to explain the apastron observations noted earlier. A statistical analysis of the eclipses from EXO0748-676 is also described
Using the Big Ideas in Cosmology to Teach College Students
Recent advances in our understanding of the Universe have revolutionized our
view of its structure, composition and evolution. However, these new ideas have
not necessarily been used to improve the teaching of introductory astronomy
students. In this project, we have conducted research into student
understanding of cosmological ideas so as to develop effective web-based tools
to teach basic concepts important to modern cosmology. The tools are intended
for use at the introductory college level. Our research uses several
instruments, including open-ended and multiple choice surveys conducted at
multiple institutions, as well as interviews and course artifacts at one
institution, to ascertain what students know regarding modern cosmological
ideas, what common misunderstandings and misconceptions they entertain, and
what sorts of materials can most effectively overcome student difficulties in
learning this material. These data are being used to create a suite of
interactive, web-based tutorials that address the major ideas in cosmology
using real data. Having students engage with real data is a powerful means to
help students overcome certain misconceptions. Students master the scientific
concepts and reasoning processes that lead to our current understanding of the
universe through interactive tasks, prediction and reflection, experimentation,
and model building.Comment: 2012 Fermi Symposium proceedings - eConf C12102
Engaging Citizen Scientists to Keep Transit Times Fresh and Ensure the Efficient Use of Transiting Exoplanet Characterization Missions
This white paper advocates for the creation of a community-wide program to
maintain precise mid-transit times of exoplanets that would likely be targeted
by future platforms. Given the sheer number of targets that will require
careful monitoring between now and the launch of the next generation of
exoplanet characterization missions, this network will initially be devised as
a citizen science project -- focused on the numerous amateur astronomers, small
universities and community colleges and high schools that have access to modest
sized telescopes and off-the-shelf CCDs.Comment: White Paper submitted to Astro2020 Science Call, 5 pages, 3 figures,
community comments and involvement are welcome
Remembrances of Steve Ellmann, Still Present
In Memoriam: Steven Ellman
Engaging Citizen Scientists to Keep Transit Times Fresh and Ensure the Efficient Use of Transiting Exoplanet Characterization Missions
This white paper advocates for the creation of a community-wide program to maintain precise mid-transit times of exoplanets that would likely be targeted by future platforms. Given the sheer number of targets that will require careful monitoring between now and the launch of the next generation of exoplanet characterization missions, this network will initially be devised as a citizen science project -- focused on the numerous amateur astronomers, small universities and community colleges and high schools that have access to modest sized telescopes and off-the-shelf CCDs
Gamma-ray and radio properties of six pulsars detected by the fermi large area telescope
We report the detection of pulsed γ-rays for PSRs J0631+1036, J0659+1414, J0742-2822, J1420-6048, J1509-5850, and J1718-3825 using the Large Area Telescope on board the Fermi Gamma-ray Space Telescope (formerly known as GLAST). Although these six pulsars are diverse in terms of their spin parameters, they share an important feature: their γ-ray light curves are (at least given the current count statistics) single peaked. For two pulsars, there are hints for a double-peaked structure in the light curves. The shapes of the observed light curves of this group of pulsars are discussed in the light of models for which the emission originates from high up in the magnetosphere. The observed phases of the γ-ray light curves are, in general, consistent with those predicted by high-altitude models, although we speculate that the γ-ray emission of PSR J0659+1414, possibly featuring the softest spectrum of all Fermi pulsars coupled with a very low efficiency, arises from relatively low down in the magnetosphere. High-quality radio polarization data are available showing that all but one have a high degree of linear polarization. This allows us to place some constraints on the viewing geometry and aids the comparison of the γ-ray light curves with high-energy beam models
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The Nuclear Spectroscopic Telescope Array (NuSTAR) High-Energy X-Ray Mission
The Nuclear Spectroscopic Telescope Array (NuSTAR) mission, launched on 2012 June 13, is the first focusing high-energy X-ray telescope in orbit. NuSTAR operates in the band from 3 to 79 keV, extending the sensitivity of focusing far beyond the ~10 keV high-energy cutoff achieved by all previous X-ray satellites. The inherently low background associated with concentrating the X-ray light enables NuSTAR to probe the hard X-ray sky with a more than 100-fold improvement in sensitivity over the collimated or coded mask instruments that have operated in this bandpass. Using its unprecedented combination of sensitivity and spatial and spectral resolution, NuSTAR will pursue five primary scientific objectives: (1) probe obscured active galactic nucleus (AGN) activity out to the peak epoch of galaxy assembly in the universe (at z lsim 2) by surveying selected regions of the sky; (2) study the population of hard X-ray-emitting compact objects in the Galaxy by mapping the central regions of the Milky Way; (3) study the non-thermal radiation in young supernova remnants, both the hard X-ray continuum and the emission from the radioactive element 44Ti; (4) observe blazars contemporaneously with ground-based radio, optical, and TeV telescopes, as well as with Fermi and Swift, to constrain the structure of AGN jets; and (5) observe line and continuum emission from core-collapse supernovae in the Local Group, and from nearby Type Ia events, to constrain explosion models. During its baseline two-year mission, NuSTAR will also undertake a broad program of targeted observations. The observatory consists of two co-aligned grazing-incidence X-ray telescopes pointed at celestial targets by a three-axis stabilized spacecraft. Deployed into a 600 km, near-circular, 6° inclination orbit, the observatory has now completed commissioning, and is performing consistent with pre-launch expectations. NuSTAR is now executing its primary science mission, and with an expected orbit lifetime of 10 yr, we anticipate proposing a guest investigator program, to begin in late 2014.Astronom
NASA Astrophysics Educator Ambassador Program
The NASA Astrophysics Educator Ambassador (EA) Program began in 2001 as part of the GLAST (now Fermi) EPO effort at Sonoma State University. The program currently supports 15 EAs, sponsored by either Fermi (10), Swift (3), XMM-Newton (1) or NuSTAR (1). This group of master educators work with mission scientists and EPO personnel to develop curricula and train teachers; they also do workshops for students and outreach events with the general public. Every other year since 2002 the EAs assemble for a week of training at SSU. Each training has had a different focus. Additionally, time is given for the EAs to share ideas from their own workshops. In the
dozen years of the program, the total number of teachers attending EA-run workshops is over 60,000, and EA workshops have received outstanding positive reviews from
participants according to surveys conducted by our external evaluator, WestEd. This poster gives an overview of the program and its nationwide impact