---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
_id: '18868'
abstract:
- lang: eng
  text: We develop two new highly efficient estimators to measure the polarization
    (Stokes parameters) in experiments that constrain the position angle of individual
    photons such as scattering and gas-pixel-detector polarimeters, and analyse in
    detail a previously proposed estimator. All three of these estimators are at least
    fifty percent more efficient on typical datasets than the standard estimator used
    in the field. We present analytic estimates of the variance of these estimators
    and numerical experiments to verify these estimates. Two of the three estimators
    can be calculated quickly and directly through summations over the measurements
    of individual photons.
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Jeremy
  full_name: Heyl, Jeremy
  last_name: Heyl
- first_name: Denis
  full_name: González-Caniulef, Denis
  last_name: González-Caniulef
- first_name: Ilaria
  full_name: Caiazzo, Ilaria
  id: 8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d
  last_name: Caiazzo
  orcid: 0000-0002-4770-5388
citation:
  ama: Heyl J, González-Caniulef D, Caiazzo I. Optimal summary statistics for X-ray
    polarization. <i>The Open Journal of Astrophysics</i>. 2024;7. doi:<a href="https://doi.org/10.33232/001c.117476">10.33232/001c.117476</a>
  apa: Heyl, J., González-Caniulef, D., &#38; Caiazzo, I. (2024). Optimal summary
    statistics for X-ray polarization. <i>The Open Journal of Astrophysics</i>. Maynooth
    Academic Publishing. <a href="https://doi.org/10.33232/001c.117476">https://doi.org/10.33232/001c.117476</a>
  chicago: Heyl, Jeremy, Denis González-Caniulef, and Ilaria Caiazzo. “Optimal Summary
    Statistics for X-Ray Polarization.” <i>The Open Journal of Astrophysics</i>. Maynooth
    Academic Publishing, 2024. <a href="https://doi.org/10.33232/001c.117476">https://doi.org/10.33232/001c.117476</a>.
  ieee: J. Heyl, D. González-Caniulef, and I. Caiazzo, “Optimal summary statistics
    for X-ray polarization,” <i>The Open Journal of Astrophysics</i>, vol. 7. Maynooth
    Academic Publishing, 2024.
  ista: Heyl J, González-Caniulef D, Caiazzo I. 2024. Optimal summary statistics for
    X-ray polarization. The Open Journal of Astrophysics. 7.
  mla: Heyl, Jeremy, et al. “Optimal Summary Statistics for X-Ray Polarization.” <i>The
    Open Journal of Astrophysics</i>, vol. 7, Maynooth Academic Publishing, 2024,
    doi:<a href="https://doi.org/10.33232/001c.117476">10.33232/001c.117476</a>.
  short: J. Heyl, D. González-Caniulef, I. Caiazzo, The Open Journal of Astrophysics
    7 (2024).
date_created: 2025-01-21T15:54:16Z
date_published: 2024-05-01T00:00:00Z
date_updated: 2025-01-27T10:48:19Z
day: '01'
doi: 10.33232/001c.117476
extern: '1'
external_id:
  arxiv:
  - '2311.07805'
intvolume: '         7'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.33232/001c.117476
month: '05'
oa: 1
oa_version: Published Version
publication: The Open Journal of Astrophysics
publication_identifier:
  issn:
  - 2565-6120
publication_status: published
publisher: Maynooth Academic Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: Optimal summary statistics for X-ray polarization
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 7
year: '2024'
...
---
_id: '17566'
abstract:
- lang: eng
  text: The formation of supermassive stars has generally been studied under the assumption
    of rapid accretion of pristine metal-free gas. Recently it was found, however,
    that gas enriched to metallicities up to Z∼10−3 Z⊙ can also facilitate supermassive
    star formation, as long as the total mass infall rate onto the protostar remains
    sufficiently high. We extend the analysis further by examining how the abundance
    of supermassive star candidate haloes would be affected if all haloes with super-critical
    infall rates, regardless of metallicity were included. We investigate this scenario
    by identifying all atomic cooling haloes in the Renaissance simulations with central
    mass infall rates exceeding a fixed threshold. We find that among these haloes
    with central mass infall rates above 0.1 M⊙ yr−1 approximately two-thirds of these
    haloes have metallicities of Z>10−3 Z⊙. If metal mixing within these haloes is
    inefficient early in their assembly and pockets of metal-poor gas can remain then
    the number of haloes hosting supermassive stars can be increased by at least a
    factor of four. Additionally the centres of these high infall-rate haloes provide
    ideal environments in which to grow pre-existing black holes. Further research
    into the (supermassive) star formation dynamics of rapidly collapsing haloes,
    with inhomogeneous metal distributions, is required to gain more insight into
    both supermassive star formation in early galaxies as well as early black hole
    growth.
article_processing_charge: No
article_type: original
author:
- first_name: John A.
  full_name: Regan, John A.
  last_name: Regan
- first_name: Zoltán
  full_name: Haiman, Zoltán
  id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36
  last_name: Haiman
- first_name: John H.
  full_name: Wise, John H.
  last_name: Wise
- first_name: Brian W.
  full_name: O'Shea, Brian W.
  last_name: O'Shea
- first_name: Michael L.
  full_name: Norman, Michael L.
  last_name: Norman
citation:
  ama: Regan JA, Haiman Z, Wise JH, O’Shea BW, Norman ML. Massive star formation in
    metal-enriched haloes at high redshift. <i>The Open Journal of Astrophysics</i>.
    2020;3(1). doi:<a href="https://doi.org/10.21105/astro.2006.14625">10.21105/astro.2006.14625</a>
  apa: Regan, J. A., Haiman, Z., Wise, J. H., O’Shea, B. W., &#38; Norman, M. L. (2020).
    Massive star formation in metal-enriched haloes at high redshift. <i>The Open
    Journal of Astrophysics</i>. Maynooth University. <a href="https://doi.org/10.21105/astro.2006.14625">https://doi.org/10.21105/astro.2006.14625</a>
  chicago: Regan, John A., Zoltán Haiman, John H. Wise, Brian W. O’Shea, and Michael
    L. Norman. “Massive Star Formation in Metal-Enriched Haloes at High Redshift.”
    <i>The Open Journal of Astrophysics</i>. Maynooth University, 2020. <a href="https://doi.org/10.21105/astro.2006.14625">https://doi.org/10.21105/astro.2006.14625</a>.
  ieee: J. A. Regan, Z. Haiman, J. H. Wise, B. W. O’Shea, and M. L. Norman, “Massive
    star formation in metal-enriched haloes at high redshift,” <i>The Open Journal
    of Astrophysics</i>, vol. 3, no. 1. Maynooth University, 2020.
  ista: Regan JA, Haiman Z, Wise JH, O’Shea BW, Norman ML. 2020. Massive star formation
    in metal-enriched haloes at high redshift. The Open Journal of Astrophysics. 3(1).
  mla: Regan, John A., et al. “Massive Star Formation in Metal-Enriched Haloes at
    High Redshift.” <i>The Open Journal of Astrophysics</i>, vol. 3, no. 1, Maynooth
    University, 2020, doi:<a href="https://doi.org/10.21105/astro.2006.14625">10.21105/astro.2006.14625</a>.
  short: J.A. Regan, Z. Haiman, J.H. Wise, B.W. O’Shea, M.L. Norman, The Open Journal
    of Astrophysics 3 (2020).
date_created: 2024-09-05T12:07:42Z
date_published: 2020-08-24T00:00:00Z
date_updated: 2024-09-18T13:17:51Z
day: '24'
doi: 10.21105/astro.2006.14625
extern: '1'
intvolume: '         3'
issue: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.21105/astro.2006.14625
month: '08'
oa: 1
oa_version: Published Version
publication: The Open Journal of Astrophysics
publication_identifier:
  issn:
  - 2565-6120
publication_status: published
publisher: Maynooth University
quality_controlled: '1'
scopus_import: '1'
status: public
title: Massive star formation in metal-enriched haloes at high redshift
type: journal_article
user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: 3
year: '2020'
...