Transportation Barriers Affecting Migrant Workers in Adams County, Pennsylvania

This study examines the transportation patterns and potential barriers among migrant families and workers in Adams County, Pennsylvania. The objective of this study is to determine whether barriers to transportation exist in the county, and if so, how these barriers impact the population facing them. Our study examines solutions such as more universal license policies or a potential public transportation option. To collect data and carry out our project, we distributed surveys in English and Spanish families through the Center for Public Service at Gettysburg College. We had the potential to receive responses from around 70 families, and ultimately received responses from 32 families. Our research indicates that 38% of our surveyed population do not possess driver’s licenses. Therefore, a significant portion of our surveyed population faces challenges in their right to mobility – for example, our results show challenges in accessing public goods, such as through difficulty in accessing supermarkets/ grocery stores. Most of our surveyed population report low usage of alternative modes of transportation other than private cars, specifically public transportation, whether by choice or from a lack of access. A limitation in our research design was our sample size and selection – because we found participants through an existing college program, our population is not necessarily representative of the greater Adams county migrant worker population. Further studies should investigate the inaccessibility to buses and find a more accessible range for bus stops in which all members of the community have access. Rural areas present unique challenges for travel, directly impacting migrant communities due to their challenge accessing drivers’ driver licenses and lack of modes of transportation

Localized Fast Radio Bursts Are Consistent with Magnetar Progenitors Formed in Core-collapse Supernovae

With the localization of fast radio bursts (FRBs) to galaxies similar to the Milky Way and the detection of a bright radio burst from SGR J1935+2154 with energy comparable to extragalactic radio bursts, a magnetar origin for FRBs is evident. By studying the environments of FRBs, evidence for magnetar formation mechanisms not observed in the Milky Way may become apparent. In this Letter, we use a sample of FRB host galaxies and a complete sample of core-collapse supernova (CCSN) hosts to determine whether FRB progenitors are consistent with a population of magnetars born in CCSNe. We also compare the FRB hosts to the hosts of hydrogen-poor superluminous supernovae (SLSNe-I) and long gamma-ray bursts (LGRBs) to determine whether the population of FRB hosts is compatible with a population of transients that may be connected to millisecond magnetars. After using a novel approach to scale the stellar masses and star formation rates of each host galaxy to be statistically representative of z = 0 galaxies, we find that the CCSN hosts and FRBs are consistent with arising from the same distribution. Furthermore, the FRB host distribution is inconsistent with the distribution of SLSNe-I and LGRB hosts. With the current sample of FRB host galaxies, our analysis shows that FRBs are consistent with a population of magnetars born through the collapse of giant, highly magnetic stars

Localized FRBs are Consistent with Magnetar Progenitors Formed in Core-Collapse Supernovae

With the localization of fast radio bursts (FRBs) to galaxies similar to the Milky Way and the detection of a bright radio burst from SGR J1935+2154 with energy comparable to extragalactic radio bursts, a magnetar origin for FRBs is evident. By studying the environments of FRBs, evidence for magnetar formation mechanisms not observed in the Milky Way may become apparent. In this paper, we use a sample of FRB host galaxies and a complete sample of core-collapse supernova (CCSN) hosts to determine whether FRB progenitors are consistent with a population of magnetars born in CCSNe. We also compare the FRB hosts to the hosts of hydrogen-poor superluminous supernovae (SLSNe-I) and long gamma-ray bursts (LGRBs) to determine whether the population of FRB hosts is compatible with a population of transients that may be connected to millisecond magnetars. After using a novel approach to scale the stellar masses and star-formation rates of each host galaxy to be statistically representative of z=0 galaxies, we find that the CCSN hosts and FRBs are consistent with arising from the same distribution. Furthermore, the FRB host distribution is inconsistent with the distribution of SLSNe-I and LGRB hosts. With the current sample of FRB host galaxies, our analysis shows that FRBs are consistent with a population of magnetars born through the collapse of giant, highly magnetic stars

The Progenitors of Fast Radio Bursts

Fast radio bursts (FRBs) are millisecond duration pulses of radio emission that are bright enough to be seen from other galaxies. The nature of the objects that produce fast radio bursts has captivated the interest of astronomers since their discovery in 2007. The durations and energetics of FRBs imply a compact, highly magnetized progenitor, making magnetars a popular progenitor candidate. However, it is difficult to pin down the progenitors of FRBs because they occur so far away. In this thesis, I will present the Survey for Transient Astronomical Radio Emission 2 (STARE2), an experiment designed to detect FRBs in the Milky Way. I will present a formalism through which to interpret the results of this experiment and demonstrate our experiment's effectiveness with the detection of a solar burst. Using STARE2, we discovered the first FRB that originated within the Milky Way, FRB 200428. This FRB was traced back to the Galactic magnetar SGR J1935+2154. The energetics, spectro-temporal properties, host galaxy, environment, and X-ray counterpart are all consistent with the properties of extragalactic FRBs. In addition, the high volumetric rate of these bright radio bursts from magnetars is consistent with the volumetric rate of FRBs, implying that magnetars are the dominant channel of FRB production. I will then develop a novel statistical technique to compare transient host galaxies in order to evaluate whether the hosts of extragalactic FRBs are consistent with a magnetar origin. I will find that the hosts of FRBs are consistent with the hosts of core-collapse supernovae, supporting the hypothesis that magnetars produce FRBs. Finally, I will present two ideas for future observing campaigns to find FRBs from M82 and more extremely bright pulses from Galactic magnetars.</p

A fast radio burst associated with a Galactic magnetar

Since their discovery in 2007, much effort has been devoted to uncovering the sources of the extragalactic, millisecond-duration fast radio bursts (FRBs). A class of neutron star known as magnetars is a leading candidate source of FRBs. Magnetars have surface magnetic fields in excess of $10^{14}$ G, the decay of which powers a range of high-energy phenomena. Here we present the discovery of a millisecond-duration radio burst from the Galactic magnetar SGR 1935+2154, with a fluence of $1.5\pm 0.3$ Mega-Jansky milliseconds. This event, termed ST 200428A(=FRB 200428), was detected on 28 April 2020 by the STARE2 radio array in the 1281--1468\,MHz band. The isotropic-equivalent energy released in ST 200428A is $4\times10^{3}$ times greater than in any Galactic radio burst previously observed on similar timescales. ST 200428A is just 40 times less energetic than the weakest extragalactic FRB observed to date, and is arguably drawn from the same population as the observed FRB sample. The coincidence of ST 200428A with an X-ray burst favours emission models developed for FRBs that describe synchrotron masers or electromagnetic pulses powered by magnetar bursts and giant flares. The discovery of ST 200428A implies that active magnetars like SGR 1935+2154 can produce FRBs at extragalactic distances. The high volumetric rate of events like ST 200428A motivates dedicated searches for similar bursts from nearby galaxies.Comment: 23 pages, 7 figures, 2 tables. Submitted to Natur

STARE2: Detecting Fast Radio Bursts in the Milky Way

There are several unexplored regions of the short-duration radio transient phase space. One such unexplored region is the luminosity gap between giant pulses (from pulsars) and cosmologically located fast radio bursts (FRBs). The Survey for Transient Astronomical Radio Emission 2 (STARE2) is a search for such transients out to 7 Mpc. STARE2 has a field of view of 3.6 steradians and is sensitive to 1 millisecond transients above ~300 kJy. With a two-station system we have detected and localized a solar burst, demonstrating that the pilot system is capable of detecting short duration radio transients. We found no convincing non-solar transients with duration between 65 μs and 34 ms in 200 days of observing, limiting with 95% confidence the all-sky rate of transients above ~300 kJy to <40 sky⁻¹ yr⁻¹. If the luminosity function of FRBs could be extrapolated down to 300 kJy for a distance of 10 kpc, then one would expect the rate to be ~2 sky⁻¹ yr⁻¹

STARE2: Detecting Fast Radio Bursts in the Milky Way

There are several unexplored regions of the short-duration radio transient phase space. One such unexplored region is the luminosity gap between giant pulses (from pulsars) and cosmologically located fast radio bursts (FRBs). The Survey for Transient Astronomical Radio Emission 2 (STARE2) is a search for such transients out to 7 Mpc. STARE2 has a field of view of 3.6 steradians and is sensitive to 1 millisecond transients above ~300 kJy. With a two-station system we have detected and localized a solar burst, demonstrating that the pilot system is capable of detecting short duration radio transients. We found no convincing non-solar transients with duration between 65 μs and 34 ms in 200 days of observing, limiting with 95% confidence the all-sky rate of transients above ~300 kJy to <40 sky⁻¹ yr⁻¹. If the luminosity function of FRBs could be extrapolated down to 300 kJy for a distance of 10 kpc, then one would expect the rate to be ~2 sky⁻¹ yr⁻¹