Searching for Millisecond Pulsars: Surveys, Techniques and Prospects

Searches for millisecond pulsars (which we here loosely define as those with periods $<$ 20 ms) in the Galactic field have undergone a renaissance in the past five years. New or recently refurbished radio telescopes utilizing cooled receivers and state-of-the art digital data acquisition systems are carrying out surveys of the entire sky at a variety of radio frequencies. Targeted searches for millisecond pulsars in point sources identified by the {\it Fermi} Gamma-ray Space Telescope have proved phenomenally successful, with over 50 discoveries in the past five years. The current sample of millisecond pulsars now numbers almost 200 and, for the first time in 25 years, now outnumbers their counterparts in Galactic globular clusters. While many of these searches are motivated to find pulsars which form part of pulsar timing arrays, a wide variety of interesting systems are now being found. Following a brief overview of the millisecond pulsar phenomenon, we describe these searches and present some of the highlights of the new discoveries in the past decade. We conclude with predictions and prospects for ongoing and future surveys.Comment: 16 pages, 3 figures, accepted for publication in Classical and Quantum gravit

Science and Literature: An Exploration Through a Shared Language

Science and fiction are often deemed opposing forces, incompatible “languages” and “cultures.” Science is the realm of fact and reality while fiction is mere fantasy, useless to the rational mind. Yet, the works of Jules Verne, Mary Shelley, Aldous Huxley, H.G. Wells, and numerous others continue to stand the test of time even as scientific knowledge and understanding broaden. Science and fiction, science and literature, are so often thought of as separate, irreconcilable entities and yet science fiction enraptures and intrigues. Science fiction is the playground of science. Where science has not yet or cannot dare to go, science fiction leaps forward eagerly. This creative thesis seeks to demonstrate a bridge between science and literature through a collection of original science fiction poems. This exploration is a culmination of research into the relationship between science and literature through scholarship and works of fiction, poetry’s relationship to both subjects, and scientific research into artificial intelligence, deep space travel, and time travel. The chapbook produced, The Silver Dark, uses science fiction as the thematic backdrop for the demonstration that science and literature can be and are connected through poetry, while also communicating complex scientifically accurate (with only a few artistic liberties) concepts in verse

Stakeholder Salience And Corporate Social Responsibility: Evidence From Three Companies

In this paper, we examine the corporate social responsibility (CSR) efforts of three socially conscious companies over time by employing Mitchell et al.&rsquo;s (1997) stakeholder salience theory.&nbsp; Mitchell et al. maintain that the extent to which managers pay attention to the interests of various stakeholder groups is based on the power, legitimacy, and urgency of the claims of each group.&nbsp; Using these attributes of power, legitimacy, and urgency, we analyze how the CSR activities of Ben and Jerry&rsquo;s Ice Cream, Malden Mills, Inc., and Nova Chemicals Company have changed over time.&nbsp; Our investigation revealed that attributes of stakeholder salience shift over a firm&rsquo;s life cycle, and therefore levels of CSR activities change as well.&nbsp; For these firms, we found that power is the primary attribute of stakeholder salience driving CSR.&nbsp; That is, in order for a firm to engage in purposeful CSR activities, the stakeholder(s) pursuing a CSR agenda must possess the power to impose such an agenda on management.&nbsp; Based on the results of our analysis, we conclude that without power, legitimacy and urgency may not provide sufficient stakeholder salience to promote CSR activities.&nbsp

Institutional Impediments To Voluntary Ethics Measurement Systems: An International Perspective

Despite numerous appeals in the business ethics literature for a multiple-stakeholder perspective to corporate governance, in practice the widespread adoption of voluntary ethics measurement systems that consider multiple stakeholders remains elusive.&nbsp; In this paper, we employ an institutional economics framework to examine the legal environment in several English-speaking countries in order to determine potential constraints that might cause managers to avoid the adoption of such systems.&nbsp; Our findings indicate that in British Commonwealth countries (1) the courts tend to view stockholders as the primary corporate constituency group and (2) there is a lack of documentary privilege.&nbsp; Therefore, any internally generated metrics on ethics and corporate social responsibility matters could potentially be either trivialized or used against the corporation in court proceedings.&nbsp; Before adopting a voluntary ethics measurement system, managers should be aware of these and other potential institutional constraints that may impede such efforts

Service Learning: A Valuable Experience

In this paper, we describe how our department recently incorporated a major service learning component into the curriculum. Specifically, we employed participation in the IRS’s Volunteer Income Tax Assistance (VITA) program as an effective means of experiential and service learning for the past two years for Masters of Accountancy students. We designed a course devoted entirely to serving in a VITA program operated on a local Air Force base. Our experience confirms that service learning can be a powerful tool in teaching. It has enhanced our students’ academic and professional development. It has given significance to our mission and it has strengthened community relationships. However, recent developments have made it difficult for us to maintain this service learning project in its present form. It appears that we, like many other programs, must consider again how to implement service learning as part of our curriculum, but we will do so now with a greater appreciation and enthusiasm for its unique contributions to learning

Inherent Conflicts Of Interest In The Accounting Profession

In this paper, we critically examine three situations in the accounting/auditing profession in which conflicts of interest arise. Specifically, we describe conflicts of interest that occur (1) because audit fees are paid by the very companies being audited, (2) due to the tension built into accountants’ codes of professional ethics between the responsibility to maintain client confidentiality and the need to serve the public trust, and (3) because of most auditors’ perspective of who is their primary client. Based on our analysis, we conclude that these three inherent conflicts of interest, in the absence of some unforeseen revolutionary changes, are likely to persist within the auditing profession. We also conclude that attempts to mitigate some of these conflicts of interest through the Sarbanes-Oxley legislation have only been moderately successful. We therefore propose that audit professionals must learn to identify and manage the conflicts of interest that will likely remain a part of the profession for the indefinite future

Cultural Diversity, Country Size, And The IFRS Adoption Decision

In this paper, we empirically examine the International Financial Reporting Standards (IFRS) adoption decision of 61 countries in an attempt to determine why some countries have adopted IFRS while others, at least to this point in time, have chosen not to adopt.&nbsp; In particular, we examine the influence of cultural diversity and country size on the adoption decision.&nbsp; Our results indicate that the IFRS adoption decision is significantly related to the size of the country, while we are unable to document any cultural influences on the decision.&nbsp; Our chief result is that larger countries are less likely to adopt International Financial Reporting Standards than small countries.&nbsp; This result is consistent with the notion that larger countries have a well-established set of financial accounting and reporting standards already in place, and therefore would be reluctant to incur the costs of changing to an international set of standards

VLBI astrometry of PSR J2222-0137: a pulsar distance measured to 0.4% accuracy

The binary pulsar J2222-0137 is an enigmatic system containing a partially recycled millisecond pulsar and a companion of unknown nature. Whilst the low eccentricity of the system favors a white dwarf companion, an unusual double neutron star system is also a possibility, and optical observations will be able to distinguish between these possibilities. In order to allow the absolute luminosity (or upper limit) of the companion object to be properly calibrated, we undertook astrometric observations with the Very Long Baseline Array to constrain the system distance via a measurement of annual geometric parallax. With these observations, we measure the parallax of the J2222-0137 system to be 3.742 +0.013 -0.016 milliarcseconds, yielding a distance of 267.3 +1.2 -0.9 pc, and measure the transverse velocity to be 57.1 +0.3 -0.2 km/s. Fixing these parameters in the pulsar timing model made it possible to obtain a measurement of Shapiro delay and hence the system inclination, which shows that the system is nearly edge-on (sin i = 0.9985 +/- 0.0005). Furthermore, we were able to detect the orbital motion of J2222-0137 in our VLBI observations and measure the longitude of ascending node. The VLBI astrometry yields the most accurate distance obtained for a radio pulsar to date, and is furthermore the most accurate parallax for any radio source obtained at "low" radio frequencies (below ~5 GHz, where the ionosphere dominates the error budget). Using the astrometric results, we show the companion to J2222-0137 will be easily detectable in deep optical observations if it is a white dwarf. Finally, we discuss the implications of this measurement for future ultra-high-precision astrometry, in particular in support of pulsar timing arrays.Comment: 22 pages, 7 figures, accepted for publication in Ap

Goals, Strategies and First Discoveries of AO327, the Arecibo All-Sky 327 MHz Drift Pulsar Survey

We report initial results from AO327, a drift survey for pulsars with the Arecibo telescope at 327 MHz. The first phase of AO327 will cover the sky at declinations of -1 to 28 degrees, excluding the region within 5 degrees of the Galactic plane, where high scattering and dispersion make low-frequency surveys sub-optimal. We record data from a 57 MHz bandwidth with 1024 channels and 125 us sampling time. The 60 s transit time through the AO327 beam means that the survey is sensitive to very tight relativistic binaries even with no acceleration searches. To date we have detected 44 known pulsars with periods ranging from 3 ms to 2.21 s and discovered 24 new pulsars. The new discoveries include three millisecond pulsars, three objects with periods of a few tens of milliseconds typical of young as well as mildly recycled pulsars, a nuller, and a rotating radio transient. Five of the new discoveries are in binary systems. The second phase of AO327 will cover the sky at declinations of 28 to 38 degrees. We compare the sensitivity and search volume of AO327 to the Green Bank North Celestial Cap survey and the GBT350 drift survey, both of which operate at 350 MHz.Comment: Accepted for publication in Ap