31 research outputs found
ACCESS: Confirmation of a Clear Atmosphere for WASP-96b and a Comparison of Light Curve Detrending Techniques
One of the strongest features was observed in WASP-96b. To
confirm this novel detection, we provide a new 475-825nm transmission spectrum
obtained with Magellan/IMACS, which indeed confirms the presence of a broad
sodium absorption feature. We find the same result when reanalyzing the
400-825nm VLT/FORS2 data. We also utilize synthetic data to test the
effectiveness of two common detrending techniques: (1) a Gaussian processes
(GP) routine, and (2) common-mode correction followed by polynomial correction
(CMC+Poly). We find that both methods poorly reproduce the absolute transit
depths but maintain their true spectral shape. This emphasizes the importance
of fitting for offsets when combining spectra from different sources or epochs.
Additionally, we find that for our datasets both methods give consistent
results, but CMC+Poly is more accurate and precise. We combine the
Magellan/IMACS and VLT/FORS2 spectra with literature 800-1644nm HST/WFC3
spectra, yielding a global spectrum from 400-1644nm. We used the PLATON and
Exoretrievals retrieval codes to interpret this spectrum, and find that both
yield relatively deeper pressures where the atmosphere is optically thick at
log-pressures between and 0.29 bars,
respectively. Exoretrievals finds a solar to super-solar and log-mixing ratios of and ,
respectively, while PLATON finds an overall metallicity of
dex. Therefore, our findings are
in agreement with literature and support the inference that the terminator of
WASP-96b has few aerosols obscuring prominent features in the optical to
near-infrared (near-IR) spectrum.Comment: ACCEPT by AJ July 5th 202
Issues and challenges in the application of Husserlian phenomenology to the Lived Experience of Hate Crime and Its Legal Aftermath
The field of hate crime research addresses the presence, sources and impact of particular types of expressions of prejudice, often perceived as particularly damaging and hurtful forms of interpersonal abuse and violence. Little, if any, credible academic research seeks to vindicate the specific racist, gendered and other vicious prejudices articulated by many perpetrators of hate crime. In turn, this raises the reflexive question of the possibilities of researchers themselves ever being able to adopt a truly "unprejudiced" approach to the presence of such damaging prejudices. Can this goal be realised without a researcher necessarily losing an experientially-grounded understanding of what these meanings, values and purposes have come to mean, and how they are themselves interpretatively re-constituted anew, including within the lived experience of victims, witnesses, police, prosecutors, judges and victim support workers?
A possible philosophically-informed approach to the dilemmas posed by this topic is offered by Husserl's phenomenology. Husserl's perpetually unfinished philosophical methodology strives, with concerted if sometimes tragic reflective rigor, to "suspend," "bracket out" and "neutralise" those core presuppositions constitutive of the research field that typically pre-judge precisely whatever demands to be questioned and explored in a radically non-prejudicial manner. This study critically explores the possibilities, reflective stages and theoretical limitations of a sympathetically reconstructed Husserlian approach to hate crime, itself understood as a would-be qualitative "science of consciousness." It argues that despite its manifest tensions, gaps, ambiguities and internal contradictions, aspects of the Husserlian philosophical approach directed towards the different levels of experienced hate crime still retain the potential to both challenge and advance our understanding of this topic. It is the "instructive" part of "instructive failure" that this article highlights
ACCESS, LRG-BEASTS, & MOPSS: Featureless Optical Transmission Spectra of WASP-25b and WASP-124b
We present new optical transmission spectra for two hot Jupiters: WASP-25b (M
= 0.56~M; R = 1.23 R; P =~3.76 days) and WASP-124b (M = 0.58~M; R =
1.34 R; P = 3.37 days), with wavelength coverages of 4200 - 9100\AA\ and
4570 - 9940\AA, respectively. These spectra are from the ESO Faint Object
Spectrograph and Camera (v.2) mounted on the New Technology Telescope (NTT) and
Inamori-Magellan Areal Camera & Spectrograph on Magellan Baade. No strong
spectral features were found in either spectra, with the data probing 4 and 6
scale heights, respectively. \texttt{Exoretrievals} and \texttt{PLATON}
retrievals favor stellar activity for WASP-25b, while the data for WASP-124b
did not favor one model over another. For both planets the retrievals found a
wide range in the depths where the atmosphere could be optically thick
( - 0.2 bars for WASP-25b and 1.6 -- 32 bars for WASP-124b)
and recovered a temperature that is consistent with the planets' equilibrium
temperatures, but with wide uncertainties (up to 430K). For
WASP-25b, the models also favor stellar spots that are 500-3000K
cooler than the surrounding photosphere. The fairly weak constraints on
parameters are owing to the relatively low precision of the data, with an
average precision of 840 and 1240 ppm per bin for WASP-25b and WASP-124b,
respectively. However, some contribution might still be due to an inherent
absence of absorption or scattering in the planets' upper atmospheres, possibly
because of aerosols. We attempt to fit the strength of the sodium signals to
the aerosol-metallicity trend proposed by McGruder et al. 2023, and find
WASP-25b and WASP-124b are consistent with the prediction, though their
uncertainties are too large to confidently confirm the trend.Comment: Accepted in AJ July 202
Madness decolonized?: Madness as transnational identity in Gail Hornstein’s Agnes’s Jacket
The US psychologist Gail Hornstein’s monograph Agnes’s Jacket: A Psychologist’s Search for the Meanings of Madness (2009) is an important intervention in the identity politics of the mad movement. Hornstein offers a resignified vision of mad identity that embroiders the central trope of an “anti-colonial” struggle to reclaim the experiential world “colonized” by psychiatry. A series of literal and figurative appeals make recourse to the inner world and (corresponding) cultural world of the mad, as well as to the ethno-symbolic cultural materials of dormant nationhood. This rhetoric is augmented by a model in which the mad comprise a diaspora without an origin, coalescing into a single transnational community. The mad are also depicted as persons displaced from their metaphorical homeland, the “inner” world “colonized” by the psychiatric regime. There are a number of difficulties with Hornstein’s rhetoric, however. Her “ethnicity-and-rights” response to the oppression of the mad is symptomatic of Western parochialism, while her proposed transmutation of putative psychopathology from limit upon identity to parameter of successful identity is open to contestation. Moreover, unless one accepts Hornstein’s porous vision of mad identity, her self-ascribed insider status in relation to the mad community may present a problematic “re-colonization” of mad experience
ACCESS & LRG-BEASTS: a precise new optical transmission spectrum of the ultrahot Jupiter WASP-103b
We present a new ground-based optical transmission spectrum of the ultrahot
Jupiter WASP-103b (K). Our transmission spectrum is the result
of combining five new transits from the ACCESS survey and two new transits from
the LRG-BEASTS survey with a reanalysis of three archival Gemini/GMOS transits
and one VLT/FORS2 transit. Our combined 11-transit transmission spectrum covers
a wavelength range of 3900--9450A with a median uncertainty in the transit
depth of 148 parts-per-million, which is less than one atmospheric scale height
of the planet. In our retrieval analysis of WASP-103b's combined optical and
infrared transmission spectrum, we find strong evidence for unocculted bright
regions () and weak evidence for HO (), HCN
(), and TiO (), which could be responsible for
WASP-103b's observed temperature inversion. Our optical transmission spectrum
shows significant structure that is in excellent agreement with the extensively
studied ultrahot Jupiter WASP-121b, for which the presence of VO has been
inferred. For WASP-103b, we find that VO can only provide a reasonable fit to
the data if its abundance is implausibly high and we do not account for stellar
activity. Our results highlight the precision that can be achieved by
ground-based observations and the impacts that stellar activity from F-type
stars can have on the interpretation of exoplanet transmission spectra.Comment: 33 pages, 17 figures, 7 tables. Accepted for publication in A
ACCESS: Confirmation of no potassium in the atmosphere of WASP-31b
We present a new optical (400-950nm) transmission spectrum of the hot Jupiter
WASP-31b (M=0.48 MJ; R= 1.54 RJ; P=3.41 days), obtained by combining four
transits observations. These transits were observed with IMACS on the Magellan
Baade Telescope at Las Campanas Observatory as part of the ACCESS project. We
investigate the presence of clouds/hazes in the upper atmosphere of this planet
as well as the contribution of stellar activity on the observed features. In
addition, we search for absorption features of the alkali elements Na I and K
I, with particular focus on K I, for which there have been two previously
published disagreeing results. Observations with HST/STIS detected K I, whereas
ground-based low- and high-resolution observations did not. We use equilibrium
and non-equilibrium chemistry retrievals to explore the planetary and stellar
parameter space of the system with our optical data combined with existing
near-IR observations. Our best-fit model is that with a scattering slope
consistent with a Rayleigh slope (alpha=5.3+2.9-3.1), high-altitude clouds at a
log cloud top pressure of -3.6+2.7-2.1 bars, and possible muted H2O features.
We find that our observations support other ground-based claims of no K I.
Clouds are likely why signals like H2O are extremely muted and Na or K cannot
be detected. We then juxtapose our Magellan/IMACS transmission spectrum with
existing VLT/FORS2, HST/WFC3, HST/STIS, and Spitzer observations to further
constrain the optical-to-infrared atmospheric features of the planet. We find
that a steeper scattering slope (alpha = 8.3+/-1.5) is anchored by STIS
wavelengths blueward of 400 nm and only the original STIS observations show
significant potassium signal.Comment: Accepted 14 September 2020 by A