Inferring the magnetic field vector in the quiet Sun. II. Interpreting results from the inversion of Stokes profiles

In a previous paper, we argued that the inversion of Stokes profiles applied to spectropolarimetric observations of the solar internetwork yield unrealistically large values of the inclination of the magnetic field vector ($\gamma$). This is because photon noise in Stokes $Q$ and $U$ are interpreted by the inversion code as valid signals, that leads to an overestimation of the transverse component $B_\perp$, thus the inclination $\gamma$. However, our study was based on the analysis of linear polarization signals that featured only uncorrelated noise. In this paper, we develop this idea further and study this effect in Stokes $Q$ and $U$ profiles that also show correlated noise. In addition, we extend our study to the three components of the magnetic field vector, as well as the magnetic filling factor $\alpha$. With this, we confirm the tendency to overestimate $\gamma$ when inverting linear polarization profiles that, although non-zero, are still below the noise level. We also establish that the overestimation occurs mainly for magnetic fields that are nearly vertical $\gamma \lesssim 20\deg$. This indicates that a reliable inference of the inclination of the magnetic field vector cannot be achieved by analyzing only Stokes $I$ and $V$. In addition, when inverting Stokes $Q$ and $U$ profiles below the noise, the inversion code retrieves a randomly uniform distribution of the azimuth of the magnetic field vector $\phi$. To avoid these problems, we propose only inverting Stokes profiles for which the linear polarization signals are sufficiently above the noise level. However, this approach is also biased because, in spite of allowing for a very accurate retrieval of the magnetic field vector from the selected Stokes profiles, it selects only profiles arising from highly inclined magnetic fields.Comment: Accepted for publication in Astronomy and Astrophysics. 14 pages. 7 color figure

Inferring the magnetic field vector in the quiet Sun. III. Disk variation of the Stokes profiles and isotropism of the magnetic field

We have studied the angular distribution of the magnetic field vector in the solar internetwork employing high-quality data (noise level $\sigma \approx 3\times 10^{-4}$ in units of the quiet-Sun intensity) at different latitudes recorded with the Hinode/SP instrument. Instead of applying traditional inversion codes of the radiative transfer equation to retrieve the magnetic field vector at each spatial point on the solar surface and studying the resulting distribution of the magnetic field vector, we surmised a theoretical distribution function of the magnetic field vector and used it to obtain the theoretical histograms of the Stokes profiles. These histograms were then compared to the observed ones. Any mismatch between them was ascribed to the theoretical distribution of the magnetic field vector, which was subsequently modified to produce a better fit to the observed histograms. With this method we find that Stokes profiles with signals above $2\times 10^{-3}$ (in units of the continuum intensity) cannot be explained by an isotropic distribution of the magnetic field vector. We also find that the differences between the histograms of the Stokes profiles observed at different latitudes cannot be explained in terms of line-of-sight effects. However, they can be explained by a distribution of the magnetic field vector that inherently varies with latitude. We note that these results are based on a series of assumptions that, although briefly discussed in this paper, need to be considered in more detail in the future.Comment: Accepted for publication in Astronomy and Astrophysics. 14 pages, 8 color figure

Discriminant analysis of solar bright points and faculae II. Contrast and morphology analysis

Taken at a high spatial resolution of 0.1 arcsec, Bright Points (BPs) are found to coexist with faculae in images and the latter are often resolved as adjacent striations. Understanding the properties of these different features is fundamental to carrying out proxy magnetometry. To shed light on the relationship between BPs and faculae, we studied them separately after the application of a classification method, developed and described in a previous paper) on active region images at various heliocentric angles. In this Paper, we explore different aspects of the photometric properties of BPs and faculae, namely their G-band contrast profiles, their peak contrast in G-band and continuum, as well as morphological parameters. We find that: (1) the width of the contrast profiles of the classified BPs and faculae are consistent with studies of disk center BPs at and limb faculae, which indirectly confirms the validity of our classification, (2) the profiles of limb faculae are limbward skewed on average, while near disk center they exhibit both centerward and limbward skewnesses due to the distribution of orientations of the faculae, (3) the relation between the peak contrasts of BPs and faculae and their apparent area discloses a trend reminiscent of magnetogram studies. The skewness of facular profiles provides a novel constraint for 3D MHD models of faculae. As suggested by the asymmetry and orientation of their contrast profiles, faculae near disk center could be induced by inclined fields, while apparent BPs near the limb seem to be in fact small faculae misidentified. The apparent area of BPs and faculae could be possibly exploited for proxy magnetometry

Finite size vertex corrections to the three-gluon decay widths of J/ψJ/\psi and Υ\Upsilon and a redetermination of αs(μ)\alpha_s(\mu) at μ=mc\mu=m_c and mbm_b

We calculate the corrections to the three-gluon decay widths $\Gamma_{3g}$ of $c\bar c$ and $b \bar b$ quarkonia due to the finite extension of the $Q\bar Q\to 3g$ vertex function. The widths computed with zero range vertex are reduced by a factor $\gamma$ where $\gamma=0.31$ for the $J/\psi$ and $\gamma=0.69$ for the $\Upsilon$. These large corrections necessitate a redetermination of the values $\alpha_s(\mu)$ extracted from $\Gamma_{3g}$. We find $\alpha_s(m_c)=0.28\pm.01$ and $\alpha_s(m_b)=0.20\pm.01$.Comment: 11 pages, HD-TVP-93-0

Evidence of convective rolls in a sunspot penumbra

aims: We study the recently discovered twisting motion of bright penumbral filaments with the aim of constraining their geometry and the associated magnetic field. methods: A large sunspot located 40\degr from disk center was observed at high resolution with the 1-m Swedish Solar Telescope. Inversions of multi-wavelength polarimetric data and speckle reconstructed time series of continuum images were used to determine proper motions, as well as the velocity and magnetic structure in penumbral filaments. results: The continuum movie reveals apparent lateral motions of bright and dark structures inside bright filaments oriented parallel to the limb, confirming recent Hinode results. In these filaments we measure upflows of $\approx 1.1 \mathrm{km/s}$ on their limbward side and weak downflows on their centerward side. The magnetic field in them is significantly weaker and more horizontal than in the adjacent dark filaments. conclusions: The data indicate the presence of vigorous convective rolls in filaments with a nearly horizontal magnetic field. These are separated by filaments harbouring stronger, more vertical fields. Because of reduced gas pressure, we see deeper into the latter. When observed near the limb, the disk-centerward side of the horizontal-field filaments appear bright due to the \textit{hot wall} effect known from faculae. We estimate that the convective rolls transport most of the energy needed to explain the penumbral radiative flux.Comment: 4 pages, 4 figures, letter to Astronomy & Astrophysic

The continuum intensity as a function of magnetic field I. Active region and quiet Sun magnetic elements

Small-scale magnetic fields are major contributors to the solar irradiance variations. Hence, the continuum intensity contrast of magnetic elements in the quiet Sun (QS) network and in active region (AR) plage is an essential quantity that needs to be measured reliably. By using Hinode/SP disk center data at a constant, high spatial resolution, we aim at updating results of earlier ground-based studies of contrast vs. magnetogram signal, and to look for systematic differences between AR plages and QS network. The field strength, filling factor and inclination of the field was retrieved by Milne-Eddington inversion (VFISV). As in earlier studies, we performed a pixel-by-pixel study of 630.2 nm continuum contrast vs. apparent (i.e. averaged over a pixel) longitudinal magnetic field over large fields of view in ARs and in the QS. The contrast of magnetic elements reaches larger values in the QS (on average 3.7%) than in ARs (1.3%). This could not be attributed to any systematic difference in the chosen contrast references. At Hinode's spatial resolution, the relationship between contrast and apparent longitudinal field strength exhibits a peak at around 700 G in both the QS and ARs, whereas earlier lower resolution studies only found a peak in the QS and a monotonous decrease in ARs. We attribute this discrepancy both to our careful removal of the pores and their close surroundings affected by the telescope diffraction, as well as to the enhanced spatial resolution and very low scattered light of the Hinode Solar Optical Telescope. According to our inversions, the magnetic elements producing the peak of the contrast curves have similar properties (field strength, inclination, filling factor) in ARs and in the QS, so that the larger brightness of magnetic elements in the QS remains unexplained.Comment: 8 figures, 14 page

Pathways to Community Living Initiative – Final Evaluation Report

The Pathways to Community Living Initiative (PCLI) is a major mental health reform program led by the NSW Ministry of Health (‘the Ministry’) in collaboration with NSW Local Health Districts (LHDs). It is a key component of the whole- of-government enhancement of mental health care under the NSW Mental Health Reform 2014-2024. The PCLI represents a transformational change in the care of people with severe and persistent mental illness (SPMI) and complex needs who are, or are at risk of becoming, long-stay inpatients in NSW hospitals. This is PCLI Evaluation Report 7, the final report of the independent evaluation conducted by the Centre for Health Service Development, University of Wollongong, between January 2017 and October 2021. The report presents the summative findings of the mixed methods evaluation activities and formative information to guide continuing reform within mental health services

Different metabolic responses during incremental exercise assessed by localized 31P MRS in sprint and endurance athletes and untrained individuals

Until recently, assessment of muscle metabolism was only possible by invasive sampling. 31P magnetic resonance spectroscopy ( 31P MRS) offers a way to study muscle metabolism non-invasively. The aim of the present study was to use spatially-resolved 31P MRS to assess the metabolism of the quadriceps muscle in sprint-trained, endurance-trained and untrained individuals during exercise and recovery. 5 sprint-trained (STA), 5 endurance-trained (ETA) and 7 untrained individuals (UTI) completed one unlocalized 31P MRS session to measure phosphocreatine (PCr) recovery, and a second session in which spatially-resolved 31P MR spectra were obtained. PCr recovery time constant (τ) was significantly longer in STA (50±17 s) and UTI (41±9 s) than in ETA (30±4 s), (P\u3c0.05). PCr changes during exercise differed between the groups, but were uniform across the different components of the quadriceps within each group. pH during recovery was higher for the ETA than for the UTI (P\u3c0.05) and also higher than for the STA (P\u3c0.01). Muscle volume was greater in STA than in UTI (P\u3c0.05) but not different from ETA. Dynamic 31P MRS revealed considerable differences among endurance and sprint athletes and untrained people. This non-invasive method offers a way to quantify differences between individual muscles and muscle components in athletes compared to untrained individuals. 2013 Georg Thieme Verlag KG Stuttgart.New York

P53 IMMUNOHISTOCHEMISTRY AS A SURROGATE FOR TP53 MUTATIONAL ANALYSIS IN ENDOMETRIAL CANCER BIOPSIES

Meeting abstract from 17th Biennial Meeting of the International Gynecologic Cancer Society Kyoto, Japan September 14-16, 201