2,062 research outputs found
The enigmatic spin evolution of PSR J0537-6910: r-modes, gravitational waves and the case for continued timing
We discuss the unique spin evolution of the young X-ray pulsar PSR
J0537-6910, a system in which the regular spin down is interrupted by glitches
every few months. Drawing on the complete timing data from the Rossi X-ray
Timing Explorer (RXTE, from 1999-2011), we argue that a trend in the
inter-glitch behaviour points to an effective braking index close to ,
much larger than expected. This value is interesting because it would accord
with the neutron star spinning down due to gravitational waves from an unstable
r-mode. We discuss to what extent this, admittedly speculative, scenario may be
consistent and if the associated gravitational-wave signal would be within
reach of ground based detectors. Our estimates suggest that one may, indeed, be
able to use future observations to test the idea. Further precision timing
would help enhance the achievable sensitivity and we advocate a joint observing
campaign between the Neutron Star Interior Composition ExploreR (NICER) and the
LIGO-Virgo network.Comment: 10 pages, 4 figures, emulate ApJ forma
Modeling pulsar time noise with long term power law decay modulated by short term oscillations of the magnetic fields of neutron stars
We model the evolution of the magnetic fields of neutron stars as consisting
of a long term power-law decay modulated by short term small amplitude
oscillations. Our model predictions on the timing noise of neutron
stars agree well with the observed statistical properties and correlations of
normal radio pulsars. Fitting the model predictions to the observed data, we
found that their initial parameter implies their initial surface magnetic
dipole magnetic field strength ~ 5E14 G at ~0.4 year old and that the
oscillations have amplitude between E-8 to E-5 and period on the order of
years. For individual pulsars our model can effectively reduce their timing
residuals, thus offering the potential of more sensitive detections of
gravitational waves with pulsar timing arrays. Finally our model can also
re-produce their observed correlation and oscillations of the second derivative
of spin frequency, as well as the "slow glitch" phenomenon.Comment: 10 pages, 6 figures, submitted to IJMPD, invited talk in the 3rd
Galileo-XuGuangqi Meeting}, Beijing, China, 12-16 October 201
What Is Your Library Worth? Extension Uses Public Value Workshops in Communities
Public libraries are seeing flat or reduced funding even as demands for new services are increasing. Facing an identical problem, Extension developed a program to identify the indirect benefits to non-participants of Extension programs in order to encourage their public funding support. This educational approach was customized to public libraries and piloted with 15 libraries. Evaluations demonstrated that the approach was popular and effective in changing local practices. Strategies are shared for customizing Extension\u27s public value program so that any public program can articulate short private and public value statements
Regulation and the cost of childcare
Female labour market choices depend on the availability, affordability and quality of childcare. In this article, we evaluate different regulatory measures and their effect on both the quality and the cost of childcare. First, we analyse data on regulations and costs to estimate the effect of regulatory measures on the cost of childcare. Next, we summarize the existing literature on the effect of regulation on childcare quality. We find that regulation intended to improve quality often focuses on easily observable measures of the care environment that do not necessarily affect the quality of care but that do increase the cost. Thus, we find that the regulatory environment could be improved by eliminating costly measures that do not affect quality of care
Library Storytelling Team Guidebook
Library Storytelling Team Guidebook, Paper 1 describes how a public library can organize a team to report its advocacy stories. Section 1 addresses the question, “Should we start a library storytelling project?” Changes in the public’s willingness to fund libraries and the changing roles of libraries in the 21st century are outlined. An overview of advocacy library stories and a team approach for an effective storytelling program follow. This section concludes with pointers to determine when it may not be appropriate to start this effort. Section 2 discusses the roles of the team members and when a consultant may be needed. Nearly 65% of the content has robust Appendices and a Glossary that provide sample agendas, a release form, a story review form, and other tools. These will save you time and the need to hire a consultant.https://digitalcommons.library.umaine.edu/extension_business/1003/thumbnail.jp
Reporting Library Advocacy Stories to Increase Funding: Guidebook for Story Reporters
Reporting Library Advocacy Stories to Increase Funding: Guidebook for Story Reporters, Paper 2 describes how a public library can report advocacy stories effectively in the 21st century. Section 1 covers the basics of library advocacy stories. Section 2 describes the story plot in detail, with examples, and integrates numerous references. The Appendices and a Glossary provide a number of tools useful to Story Reporters and other key players in the library’s story telling team. Companion paper to Library Storytelling Team Guidebook, Paper 1https://digitalcommons.library.umaine.edu/extension_business/1004/thumbnail.jp
The Middleton Place Privy: A Study of Discard Behavior and the Archeological Record
https://scholarcommons.sc.edu/archanth_books/1165/thumbnail.jp
All About Maine : Print and Film Materials to Enrich the Study of Maine History in Grade Eight
All About Maine: Print and Film Materials to Enrich the Study of Maine History in Grade Eight. By Clyde W. Swett, Consultant Instructional Media, Department of Education and Mary L. Haskell, Librarian Union Street Junior High School, Bangor.
Maine State Department of Education, Augusta, 1969.
Contents under the following headings: Biography, Fiction, Films, Folklore, Literature, Maps, Miscellaneous, Natural History and Geology, Periodicals, Social and Political History, Directory of Publishers and Distributors, Index.https://digitalcommons.usm.maine.edu/me_collection/1011/thumbnail.jp
How Does Our Local Library Benefit My Family?
Libraries benefit everyone in their community, not only library users but also those that never use it.https://digitalcommons.library.umaine.edu/extension_business/1002/thumbnail.jp
Gravitational waves from rapidly rotating neutron stars
Rapidly rotating neutron stars in Low Mass X-ray Binaries have been proposed
as an interesting source of gravitational waves. In this chapter we present
estimates of the gravitational wave emission for various scenarios, given the
(electromagnetically) observed characteristics of these systems. First of all
we focus on the r-mode instability and show that a 'minimal' neutron star model
(which does not incorporate exotica in the core, dynamically important magnetic
fields or superfluid degrees of freedom), is not consistent with observations.
We then present estimates of both thermally induced and magnetically sustained
mountains in the crust. In general magnetic mountains are likely to be
detectable only if the buried magnetic field of the star is of the order of
G. In the thermal mountain case we find that gravitational
wave emission from persistent systems may be detected by ground based
interferometers. Finally we re-asses the idea that gravitational wave emission
may be balancing the accretion torque in these systems, and show that in most
cases the disc/magnetosphere interaction can account for the observed spin
periods.Comment: To appear in 'Gravitational Waves Astrophysics: 3rd Session of the
Sant Cugat Forum on Astrophysics, 2014', Editor: Carlos F. Sopuert
- …