---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '23151'
abstract:
- lang: eng
  text: "We present deep, narrowband Gemini North/GMOS images of the Pa 30 nebula
    that reveal rich small-scale\r\nstructure in the ejecta filaments. In [S II],
    the number of detected filaments increases by about an order of\r\nmagnitude compared
    to previous studies. The imaging further reveals that the filaments are not smooth
    radial\r\nstreaks, but instead are composed of cascades of knots or clumps. The
    images in [O III] yield the first confirmation\r\nthat previously detected diffuse
    [O III] emission in fact originates from the same [S II] filaments. We measure
    a\r\nnebula center consistent with the position of the central star, indicating
    that the remnant has not received a large\r\ntransverse kick. The 3σ upper limit
    on the velocity of the stellar kick is ≲100 km s\r\n−1\r\n. Cross-sectional profiles
    of\r\nthe filaments in [S II] and [O III] show a central peak on top of a nebula
    background, the latter being likely due to\r\ndiffuse emission or unresolved filaments.
    The median [S II] width of 0.7 is slightly broader than the 0.50 seeing,\r\nproviding
    some evidence of partially resolved filaments and implying a characteristic knot
    diameter of ∼1016 cm.\r\nThe ≈1″ widths measured in [O III] are consistent with
    the poorer seeing of the oxygen images. The discovery of\r\nthis clumpy substructure
    provides a new observational constraint on models for the origin and evolution
    of the\r\nremarkable filamentary ejecta of Pa 30."
acknowledgement: "We thank Jim Fuller, SR Kulkarni, David Charbonneau, Paul Duffell,
  Abigail Polin, Miranda Pikus, Tony Piro, Lars Bildsten, Eliot Quartert, and Rob
  Fesen for helpful discussions. This work was supported by NASA through the NASA
  Hubble Fellowship grant HST-HF2-51527.001-A awarded by the Space Telescope Science
  Institute, which is operated by the Association of Universities for Research in
  Astronomy, Inc., for NASA, under contract NAS5-26555.\r\n\r\nFacility: Gemini:Gillett
  (GMOS-N) - .\r\n\r\nSoftware: astropy (Astropy Collaboration et al. 2013, 2018),
  scipy (P. Virtanen et al. 2020), emcee (D. Foreman-Mackey et al. 2013), DRAGONS
  (K. Labrie et al. 2023), DS9 (W. A. Joye & E. Mandel 2003)."
article_number: '28'
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Tim
  full_name: Cunningham, Tim
  last_name: Cunningham
- first_name: Ilaria
  full_name: Caiazzo, Ilaria
  id: 8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d
  last_name: Caiazzo
  orcid: 0000-0002-4770-5388
- first_name: John C.
  full_name: Raymond, John C.
  last_name: Raymond
- first_name: Scott J.
  full_name: Kenyon, Scott J.
  last_name: Kenyon
citation:
  ama: Cunningham T, Caiazzo I, Raymond JC, Kenyon SJ. Detection of knots in the type
    Iax supernova remnant Pa 30. <i>The Astrophysical Journal</i>. 2026;1010(1). doi:<a
    href="https://doi.org/10.3847/1538-4357/ae9cb2">10.3847/1538-4357/ae9cb2</a>
  apa: Cunningham, T., Caiazzo, I., Raymond, J. C., &#38; Kenyon, S. J. (2026). Detection
    of knots in the type Iax supernova remnant Pa 30. <i>The Astrophysical Journal</i>.
    IOP Publishing. <a href="https://doi.org/10.3847/1538-4357/ae9cb2">https://doi.org/10.3847/1538-4357/ae9cb2</a>
  chicago: Cunningham, Tim, Ilaria Caiazzo, John C. Raymond, and Scott J. Kenyon.
    “Detection of Knots in the Type Iax Supernova Remnant Pa 30.” <i>The Astrophysical
    Journal</i>. IOP Publishing, 2026. <a href="https://doi.org/10.3847/1538-4357/ae9cb2">https://doi.org/10.3847/1538-4357/ae9cb2</a>.
  ieee: T. Cunningham, I. Caiazzo, J. C. Raymond, and S. J. Kenyon, “Detection of
    knots in the type Iax supernova remnant Pa 30,” <i>The Astrophysical Journal</i>,
    vol. 1010, no. 1. IOP Publishing, 2026.
  ista: Cunningham T, Caiazzo I, Raymond JC, Kenyon SJ. 2026. Detection of knots in
    the type Iax supernova remnant Pa 30. The Astrophysical Journal. 1010(1), 28.
  mla: Cunningham, Tim, et al. “Detection of Knots in the Type Iax Supernova Remnant
    Pa 30.” <i>The Astrophysical Journal</i>, vol. 1010, no. 1, 28, IOP Publishing,
    2026, doi:<a href="https://doi.org/10.3847/1538-4357/ae9cb2">10.3847/1538-4357/ae9cb2</a>.
  short: T. Cunningham, I. Caiazzo, J.C. Raymond, S.J. Kenyon, The Astrophysical Journal
    1010 (2026).
corr_author: '1'
das_tickbox: '0'
date_created: 2026-10-18T22:01:51Z
date_published: 2026-10-10T00:00:00Z
date_updated: 2026-10-19T06:59:28Z
day: '10'
ddc:
- '520'
department:
- _id: IlCa
doi: 10.3847/1538-4357/ae9cb2
external_id:
  arxiv:
  - '2610.06424'
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fulldoi: https://doi.org/10.3847/1538-4357/ae9cb2
has_accepted_license: '1'
intvolume: '      1010'
issue: '1'
language:
- iso: eng
month: '10'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
  eissn:
  - 1538-4357
  issn:
  - 0004-637X
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
researchdata_availability: no
scopus_import: '1'
status: public
supplementarymaterial: yes
title: Detection of knots in the type Iax supernova remnant Pa 30
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