ABSTRACT
This paper describes the rapidly evolving and unusual supernova LSQ13ddu, discovered by the La Silla-QUEST survey. LSQ13ddu displayed a rapid rise of just 4.8 ± 0.9 d to reach a peak ...brightness of −19.70 ± 0.02 mag in the LSQgr band. Early spectra of LSQ13ddu showed the presence of weak and narrow $\mathrm{ He}\, {\small I}$ features arising from interaction with circumstellar material (CSM). These interaction signatures weakened quickly, with broad features consistent with those seen in stripped-envelope SNe becoming dominant around two weeks after maximum. The narrow $\mathrm{ He}\, {\small I}$ velocities are consistent with the wind velocities of luminous blue variables but its spectra lack the typically seen hydrogen features. The fast and bright early light curve is inconsistent with radioactive 56Ni powering but can be explained through a combination of CSM interaction and an underlying 56Ni decay component that dominates the later time behaviour of LSQ13ddu. Based on the strength of the underlying broad features, LSQ13ddu appears deficient in He compared to standard SNe Ib.
Abstract We present an analysis of ground-based and JWST observations of SN 2022pul, a peculiar “03fg-like” (or “super-Chandrasekhar”) Type Ia supernova (SN Ia), in the nebular phase at 338 days ...postexplosion. Our combined spectrum continuously covers 0.4–14 μ m and includes the first mid-infrared spectrum of a 03fg-like SN Ia. Compared to normal SN Ia 2021aefx, SN 2022pul exhibits a lower mean ionization state, asymmetric emission-line profiles, stronger emission from the intermediate-mass elements (IMEs) argon and calcium, weaker emission from iron-group elements (IGEs), and the first unambiguous detection of neon in a SN Ia. A strong, broad, centrally peaked Ne ii line at 12.81 μ m was previously predicted as a hallmark of “violent merger” SN Ia models, where dynamical interaction between two sub- M Ch white dwarfs (WDs) causes disruption of the lower-mass WD and detonation of the other. The violent merger scenario was already a leading hypothesis for 03fg-like SNe Ia; in SN 2022pul it can explain the large-scale ejecta asymmetries seen between the IMEs and IGEs and the central location of narrow oxygen and broad neon. We modify extant models to add clumping of the ejecta to reproduce the optical iron emission better, and add mass in the innermost region (<2000 km s −1 ) to account for the observed narrow O i λ λ 6300, 6364 emission. A violent WD–WD merger explains many of the observations of SN 2022pul, and our results favor this model interpretation for the subclass of 03fg-like SNe Ia.
Abstract
We present the discovery of ZTF 21aaoryiz/SN 2021fcg—an extremely low luminosity Type Iax supernova. SN 2021fcg was discovered by the Zwicky Transient Facility in the star-forming galaxy ...IC0512 at a distance of ≈27 Mpc. It reached a peak absolute magnitude of
M
r
= −12.66 ± 0.20 mag, making it the least luminous thermonuclear supernova discovered to date. The
E
(
B
−
V
) contribution from the underlying host galaxy is unconstrained. However, even if it were as large as 0.5 mag, the peak absolute magnitude would be
M
r
= −13.78 ± 0.20 mag—still consistent with being the lowest-luminosity SN. Optical spectra of SN 2021fcg taken at 37 and 65 days post-maximum show strong Ca
ii
, Ca
ii
, and Na
i
D emission and several weak Fe
ii
emission lines. The Ca
ii
emission in the two spectra has extremely low velocities of ≈1300 and 1000 km s
−1
, respectively. The spectra very closely resemble those of the very low luminosity Type Iax supernovae SN 2008 ha, SN 2010ae, and SN 2019gsc taken at similar phases. The peak bolometric luminosity of SN 2021fcg is ≈
2.5
−
0.3
+
1.5
×
10
40
erg s
−1
, which is a factor of 3 lower than that for SN 2008 ha. The bolometric lightcurve of SN 2021fcg is consistent with a very low ejected nickel mass (
M
Ni
≈
0.8
−
0.5
+
0.4
×
10
−
3
M
⊙
). The low luminosity and nickel mass of SN 2021fcg pose a challenge to the picture that low-luminosity SNe Iax originate from deflagrations of near-
M
ch
hybrid carbon–oxygen–neon white dwarfs. Instead, the merger of a carbon–oxygen and oxygen–neon white dwarf is a promising model to explain SN 2021fcg.
Care needs to be taken in the process of making - and writing about - dance, theatre, and performance. Performers with disability and dementia highlight this need because the stakes are raised. Yet a ...'sticky' paradox emerges. Disability rights activists are critical of care to the point of dangerous devaluation. 'Who cares?' They may say, in all earnestness. Yet, we must listen because of the history of abuse, neglect, and oppression of disabled people and people with dementia in the name of care, which continues today.
Mobilising disability scholarship and disability performance theory Maguire-Rosier and Gibson critique unproblematised care theories and disability rights discourses, which are largely anti-care, pressing their argument through an investigation of acts of disclosure - both on stage and off - by artists with disability and performers living with dementia. These acts interrogate medical narratives of disability and disease, giving rise to a tension - a resistance to, and an embrace of, 'care'. Maguire-Rosier presses her argument by examining Sydney-based Murmuration's creative development of dance theatre work, Days Like These (2017), calling for acts of disclosure to be understood as performances of care. Gibson responds to Maguire-Rosier 's concerns by examining To Whom I May Concern® (2018) at Hill House Connecticut, where people with dementia, who do not necessarily see themselves as disabled, or 'sufferers' as they are frequently labelled in the media, enact disclosure as creative expression. The article presents the contradictions inherent to care epitomised not least in the dilemma of the authors disclosing on behalf of performance practitioners in this research.
On 2011 May 31 UT a supernova (SN) exploded in the nearby galaxy M51 (the Whirlpool Galaxy). We discovered this event using small telescopes equipped with CCD cameras and also detected it with the ...Palomar Transient Factory survey, rapidly confirming it to be a Type II SN. Here, we present multi-color ultraviolet through infrared photometry which is used to calculate the bolometric luminosity and a series of spectra. Our early-time observations indicate that SN 2011dh resulted from the explosion of a relatively compact progenitor star. Rapid shock-breakout cooling leads to relatively low temperatures in early-time spectra, compared to explosions of red supergiant stars, as well as a rapid early light curve decline. Optical spectra of SN 2011dh are dominated by H lines out to day 10 after explosion, after which He I lines develop. This SN is likely a member of the cIIb (compact IIb) class, with progenitor radius larger than that of SN 2008ax and smaller than the eIIb (extended IIb) SN 1993J progenitor. Our data imply that the object identified in pre-explosion Hubble Space Telescope images at the SN location is possibly a companion to the progenitor or a blended source, and not the progenitor star itself, as its radius (~1013 cm) would be highly inconsistent with constraints from our post-explosion spectra.
This paper is about writing effective recommendations for action based on inquiries, evidence or arguments that have the purpose of effecting change. The importance of the topic for higher education ...is evident in the increasing accountability being asked of research from within institutions, in other words, research which provides evidenced-based conclusions but which need compelling recommendations for them to be acted upon. These recommendations might be for individuals or organisations and can range from the personal to the collective through a range of approaches and settings or workplaces: home, school, factory or business hub. Recommendations are calls to action that need to be persuasive if they are to convince others to act. We discuss how recommendations might be developed and presented calling firstly on the insights found in Aristotle's Rhetoric and then developing a phronetic method for presenting recommendations with the intent of helping them achieve the legitimate goals of their authors, supported by a review of 20 work-based doctorates.
Fruit firmness is an important quality attribute of ‘Hayward’ kiwifruit (Actinidia deliciosa (A. Chev) C.F. Liang et A.R. Ferguson cv. ‘Hayward’). Most studies on the variation in fruit firmness have ...focused on fruit batches, however within batch firmness variation normally exceeds that between batches. Flesh firmness of commercially packed fruit from 38 growers was measured over two years covering the main harvest season from mid April to early June in Bay of Plenty, the major kiwifruit production region of New Zealand. Fruit weight, colour (L, C, H colour space) soluble solid content, dry matter content and mineral (N, P, K, Ca and Mg) concentrations were measured on individual fruit. The relationship between firmness and other variables was established on an individual fruit basis by stepwise regression. The percentage of dry matter that had solublised (SSFDM) accounted for 73.8% of the firmness variation. Phosphorus, calcium and fruit hue angle together explained an additional 4.8% of the variation. This relationship was consistent for the validation data set. SSFDM appears to be a better index for determining physiological maturity than soluble solid content. It is concluded that firmness variation of packed kiwifruit is caused by uneven physiological maturity, differences in mineral concentrations and fruit colour.
The idea that learning involves a kind of therapy goes back to ancient times: Socrates was, at least in part, concerned with a kind of care of the self, and Plato in his early dialogues presents ...learning as a cure for bad intellectual and moral habits. Our metaphoric use of therapy supposes that worthwhile learning might be considered as a treatment for moral or physical non-well-being in that learning, like illness, might most easily be identified with a desire for good.
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