39 research outputs found
Early intervention for stigma towards mental illness? Promoting positive attitudes towards severe mental illness in primary school children
Purpose
Stigma towards severe mental illness (SMI) is widespread, exacerbating mental health problems, and impacting on help-seeking and social inclusion. Anti-stigma campaigns are meeting with success, but results are mixed. Earlier intervention to promote positive mental health literacy rather than challenge stigma, may show promise, but little is known about stigma development or interventions in younger children. This study will investigate (i) children’s knowledge, attitudes and behaviour towards SMI and (ii) whether we can positively influence children’s attitudes before stigma develops.
Design/methodology/approach
A cross sectional study investigated mental health schema in 7-11 year olds. An experimental intervention investigated whether an indirect contact story-based intervention in 7-8 year olds led to more positive mental health schema.
Findings:
Young children’s schema were initially positive, and influenced by knowledge and contact with mental illness & intergroup anxiety, but were more stigmatising in older girls as intergroup anxiety increased. The indirect contact intervention was effective in promoting positive mental health schema, partially mediated by knowledge.
Social Implications: Intervening early to shape concepts of mental illness more positively, as they develop in young children, may represent a more effective strategy than attempting to challenge and change mental health stigma once it has formed in adolescents and adults.
Originality/Value:
This study is the first to investigate an intervention targeted at the prevention of stigma towards severe mental illness, in young children, at the point that stigma is emerging
The GBT 350-MHz Drift Scan Pulsar Survey. III. Detection of a magnetic field in the eclipsing material of PSR J2256-1024
We present the first measurement of a non-zero magnetic field in the
eclipsing material of a black widow pulsar. Black widows are millisecond
pulsars which are ablating their companions; therefore they are often proposed
as one potential source of isolated millisecond pulsars. PSR J2256-1024 is an
eclipsing black widow discovered at radio wavelengths and later also observed
in the X-ray and gamma parts of the spectrum. Here we present the radio timing
solution for PSR J2256-1024, polarization profiles at 350, 820, and 1500~MHz
and an investigation of changes in the polarization profile due to eclipsing
material in the system. In the latter we find evidence of Faraday rotation in
the linear polarization shortly after eclipse, measuring a rotation measure of
0.44(6) rad per meter squared and a corresponding line-of-sight magnetic field
of 3.5(17) mG.Comment: 14 pages, 8 figure
The second set of pulsar discoveries by CHIME/FRB/Pulsar: 14 Rotating Radio Transients and 7 pulsars
The Canadian Hydrogen Mapping Experiment (CHIME) is a radio telescope located
in British Columbia, Canada. The large field of view (FOV) of 200 square
degrees has enabled the CHIME/FRB instrument to produce the largest FRB catalog
to date. The large FOV also allows CHIME/FRB to be an exceptional pulsar and
Rotating Radio Transient (RRAT) finding machine, despite saving only the
metadata information of incoming Galactic events. We have developed a pipeline
to search for pulsars/RRATs using DBSCAN, a clustering algorithm. Output
clusters are then inspected by a human for pulsar/RRAT candidates and follow-up
observations are scheduled with the more sensitive CHIME/Pulsar instrument. The
CHIME/Pulsar instrument is capable of a near-daily search mode observation
cadence. We have thus developed the CHIME/Pulsar Single Pulse Pipeline to
automate the processing of CHIME/Pulsar search mode data. We report the
discovery of 21 new Galactic sources, with 14 RRATs, 6 regular slow pulsars and
1 binary system. Owing to CHIME/Pulsar's daily observations we have obtained
timing solutions for 8 of the 14 RRATs along with all the regular pulsars. This
demonstrates CHIME/Pulsar's ability at finding timing solutions for transient
sources
Multi-Messenger Gravitational Wave Searches with Pulsar Timing Arrays: Application to 3C66B Using the NANOGrav 11-year Data Set
When galaxies merge, the supermassive black holes in their centers may form
binaries and, during the process of merger, emit low-frequency gravitational
radiation in the process. In this paper we consider the galaxy 3C66B, which was
used as the target of the first multi-messenger search for gravitational waves.
Due to the observed periodicities present in the photometric and astrometric
data of the source of the source, it has been theorized to contain a
supermassive black hole binary. Its apparent 1.05-year orbital period would
place the gravitational wave emission directly in the pulsar timing band. Since
the first pulsar timing array study of 3C66B, revised models of the source have
been published, and timing array sensitivities and techniques have improved
dramatically. With these advances, we further constrain the chirp mass of the
potential supermassive black hole binary in 3C66B to less than using data from the NANOGrav 11-year data set. This
upper limit provides a factor of 1.6 improvement over previous limits, and a
factor of 4.3 over the first search done. Nevertheless, the most recent orbital
model for the source is still consistent with our limit from pulsar timing
array data. In addition, we are able to quantify the improvement made by the
inclusion of source properties gleaned from electromagnetic data to `blind'
pulsar timing array searches. With these methods, it is apparent that it is not
necessary to obtain exact a priori knowledge of the period of a binary to gain
meaningful astrophysical inferences.Comment: 14 pages, 6 figures. Accepted by Ap
CHIME Discovery of a Binary Pulsar with a Massive Non-Degenerate Companion
Of the more than 3000 radio pulsars currently known, only ∼300 are in binary systems, and only five of these consist of young pulsars with massive nondegenerate companions. We present the discovery and initial timing, accomplished using the Canadian Hydrogen Intensity Mapping Experiment (CHIME) telescope, of the sixth such binary pulsar, PSR J2108+4516, a 0.577 s radio pulsar in a 269 day orbit of eccentricity 0.09 with a companion of minimum mass 11 M⊙. Notably, the pulsar undergoes periods of substantial eclipse, disappearing from the CHIME 400–800 MHz observing band for a large fraction of its orbit, and displays significant dispersion measure and scattering variations throughout its orbit, pointing to the possibility of a circumstellar disk or very dense stellar wind associated with the companion star. Subarcsecond resolution imaging with the Karl G. Jansky Very Large Array unambiguously demonstrates that the companion is a bright, V ≃ 11 OBe star, EM* UHA 138, located at a distance of 3.26(14) kpc. Archival optical observations of EM* UHA 138 approximately suggest a companion mass ranging from 17.5 M⊙ < Mc < 23 M⊙, in turn constraining the orbital inclination angle to 50fdg3 ≲ i ≲ 58fdg3. With further multiwavelength follow-up, PSR J2108+4516 promises to serve as another rare laboratory for the exploration of companion winds, circumstellar disks, and short-term evolution through extended-body orbital dynamics
The NANOGrav 11-Year Data Set: Arecibo Observatory Polarimetry And Pulse Microcomponents
We present the polarization pulse profiles for 28 pulsars observed with the
Arecibo Observatory by the North American Nanohertz Observatory for
Gravitational Waves (NANOGrav) timing project at 2.1 GHz, 1.4 GHz, and 430 MHz.
These profiles represent some of the most sensitive polarimetric millisecond
pulsar profiles to date, revealing the existence of microcomponents (that is,
pulse components with peak intensities much lower than the total pulse peak
intensity). Although microcomponents have been detected in some pulsars
previously, we present microcomponents for PSRs B1937+21, J1713+0747, and
J2234+0944 for the first time. These microcomponents can have an impact on
pulsar timing, geometry, and flux density determination. We present rotation
measures for all 28 pulsars, determined independently at different observation
frequencies and epochs, and find the Galactic magnetic fields derived from
these rotation measures to be consistent with current models. These
polarization profiles were made using measurement equation template matching,
which allows us to generate the polarimetric response of the Arecibo
Observatory on an epoch-by-epoch basis. We use this method to describe its time
variability, and find that the polarimetric responses of the Arecibo
Observatory's 1.4 and 2.1 GHz receivers vary significantly with time.Comment: 41 pages, 20 figure
The NANOGrav 11-year Data Set: High-precision Timing of 45 Millisecond Pulsars
We present high-precision timing data over time spans of up to 11 years for 45 millisecond pulsars observed as part of the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) project, aimed at detecting and characterizing low-frequency gravitational waves. The pulsars were observed with the Arecibo Observatory and/or the Green Bank Telescope at frequencies ranging from 327 MHz to 2.3 GHz. Most pulsars were observed with approximately monthly cadence, and six high-timing-precision pulsars were observed weekly. All were observed at widely separated frequencies at each observing epoch in order to fit for time-variable dispersion delays. We describe our methods for data processing, time-of-arrival (TOA) calculation, and the implementation of a new, automated method for removing outlier TOAs. We fit a timing model for each pulsar that includes spin, astrometric, and (for binary pulsars) orbital parameters; time-variable dispersion delays; and parameters that quantify pulse-profile evolution with frequency. The timing solutions provide three new parallax measurements, two new Shapiro delay measurements, and two new measurements of significant orbital-period variations. We fit models that characterize sources of noise for each pulsar. We find that 11 pulsars show significant red noise, with generally smaller spectral indices than typically measured for non-recycled pulsars, possibly suggesting a different origin. A companion paper uses these data to constrain the strength of the gravitational-wave background
The nanograv nine-year data set: Observations arrival time measurements and analysis of 37 millisecond pulsars
We present high-precision timing observations spanning up to nine years for 37 millisecond pulsars monitored with the Green Bank and Arecibo radio telescopes as part of the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) project. We describe the observational and instrumental setups used to collect the data, and methodology applied for calculating pulse times of arrival; these include novel methods for measuring instrumental offsets and characterizing low signal-to-noise ratio timing results. The time of arrival data are fit to a physical timing model for each source, including terms that characterize time-variable dispersion measure and frequency-dependent pulse shape evolution. In conjunction with the timing model fit, we have performed a Bayesian analysis of a parameterized timing noise model for each source, and detect evidence for excess low-frequency, or \ red,\ timing noise in 10 of the pulsars. For 5 of these cases this is likely due to interstellar medium propagation effects rather than intrisic spin variations. Subsequent papers in this series will present further analysis of this data set aimed at detecting or limiting the presence of nanohertz-frequency gravitational wave signals
Bayesian Solar Wind Modeling with Pulsar Timing Arrays
Using Bayesian analyses we study the solar electron density with the NANOGrav
11-year pulsar timing array (PTA) dataset. Our model of the solar wind is
incorporated into a global fit starting from pulse times-of-arrival. We
introduce new tools developed for this global fit, including analytic
expressions for solar electron column densities and open source models for the
solar wind that port into existing PTA software. We perform an ab initio
recovery of various solar wind model parameters. We then demonstrate the
richness of information about the solar electron density, , that can be
gleaned from PTA data, including higher order corrections to the simple
model associated with a free-streaming wind (which are informative probes of
coronal acceleration physics), quarterly binned measurements of and a
continuous time-varying model for spanning approximately one solar cycle
period. Finally, we discuss the importance of our model for chromatic noise
mitigation in gravitational-wave analyses of pulsar timing data and the
potential of developing synergies between sophisticated PTA solar electron
density models and those developed by the solar physics community.Comment: 22 pages, 7 figures, Submitted to Ap
The NANOGrav 12.5-Year Data Set: Polarimetry and Faraday Rotation Measures from Observations of Millisecond Pulsars with the Green Bank Telescope
In this work, we present polarization profiles for 23 millisecond pulsars
observed at 820 MHz and 1500 MHz with the Green Bank Telescope as part of the
NANOGrav pulsar timing array. We calibrate the data using Mueller matrix
solutions calculated from observations of PSRs B1929+10 and J1022+1001. We
discuss the polarization profiles, which can be used to constrain pulsar
emission geometry, and present both the first published radio polarization
profiles for nine pulsars and the discovery of very low intensity average
profile components ("microcomponents") in four pulsars. Using the Faraday
rotation measures, we measure for each pulsar and use it to calculate the
Galactic magnetic field parallel to the line of sight for different lines of
sight through the interstellar medium. We fit for linear and sinusoidal trends
in time in the dispersion measure and Galactic magnetic field and detect
magnetic field variations with a period of one year in some pulsars, but
overall find that the variations in these parameters are more consistent with a
stochastic origin.Comment: 35 pages, 21 figures. Accepted to Ap