To characterize circumstellar systems in high-contrast imaging, the fundamental step is to construct a best point-spread function (PSF) template for the noncircumstellar signals (i.e., starlight and ...speckles) and separate it from the observation. With existing PSF construction methods, the circumstellar signals (e.g., planets, circumstellar disks) are unavoidably altered by overfitting and/or self-subtraction, making forward modeling a necessity to recover these signals. We present a forward modeling-free solution to these problems with data imputation using sequential nonnegative matrix factorization (DI-sNMF), which first converts this signal separation problem to a "missing data" problem in statistics by flagging the regions that host circumstellar signals as missing data, then attributes PSF signals to these regions. We mathematically prove it to have negligible alteration to circumstellar signals when the imputation region is relatively small, which thus enables precise measurement of these circumstellar objects. We apply it to simulated point-source and circumstellar disk observations to demonstrate its proper recovery of them. We apply it to Gemini Planet Imager K1-band observations of the debris disk surrounding HR 4796A, finding a tentative trend that the dust is more forward scattering as the wavelength increases. We expect DI-sNMF to be applicable to other general scenarios where the separation of signals is needed.
Abstract Objective The purpose of the present study was to evaluate the relationship between various levels of parent-child physical violence and psychological symptoms reported by college students, ...while controlling for demographic variables, severity and frequency of violence, and co-occurrence of parental psychological aggression. Method Participants included 298 college students ranging in age from 18 to 27 years. Participants completed a demographic information form, the Brief Symptom Inventory (BSI), and the Parent-Child Conflict Tactics Scale (CTSPC). Results Results of analysis of variance and multivariate analysis of variance indicated that individuals in the child physical abuse group obtained higher BSI scores compared to individuals in the corporal punishment and no violence groups. Few differences were observed between mild and severe corporal punishment groups. Multiple regression analyses indicated that when frequency of corporal punishment, child physical abuse, and psychological aggression, along with demographic variables, were considered simultaneously, psychological aggression was the most unique predictor of BSI scores. Conclusions The findings suggest that severe forms of physical violence were associated with long-term psychological symptoms. When demographic variables and the frequency of several parent aggression variables were considered simultaneously, however, psychological aggression was most predictive of psychological outcome. These findings suggest that messages communicated to a child via psychological aggression may be more important in contributing to psychological outcome than the actual occurrence of physical violence toward the child. Practice implications The current study supports the premise that severe physical aggression experienced in childhood is associated with serious psychological consequences in adulthood. In contrast, individuals who experienced less severe forms of parent-child violence, such as corporal aggression, exhibited similar symptom levels to those reporting no parent-child violence. When severe physical aggression, corporal aggression, and psychological aggression were considered simultaneously, however, psychological aggression emerged as the most unique predictor of psychological outcome. Researchers and clinicians who work with adults reporting childhood histories of severe parent-child violence should be aware of the importance of parent-child psychological aggression in contributing to psychological outcome.
Abstract
The carbon-to-oxygen (C/O) ratio in an exoplanet atmosphere has been suggested as a potential diagnostic of planet formation. Now that a number of exoplanets have measured C/O ratios, it is ...possible to examine this diagnostic at a population level. Here, we present an analysis of currently measured C/O ratios of directly imaged and transit/eclipse planets. First, we derive atmospheric parameters for the substellar companion HD 284149 AB b using data taken with the OSIRIS integral field spectrograph at the W.M. Keck Observatory and report two non-detections from our ongoing imaging spectroscopy survey with Keck/OSIRIS. We find an effective temperature of
T
eff
= 2502 K, with a range of 2291–2624 K,
log
g
=
4.52
, with a range of 4.38–4.91, and M/H = 0.37, with a range of 0.10–0.55. We derive a C/O of
0.59
−
0.30
+
0.15
for HD 284149 AB b. We add this measurement to the list of C/O ratios for directly imaged planets and compare them with those from a sample of transit/eclipse planets. We also derive the first dynamical mass estimate for HD 284149 AB b, finding a mass of ∼28
M
Jup
. There is a trend in C/O ratio with companion mass (
M
Jup
), with a break seen around 4
M
Jup
. We run a Kolmogorov–Smirnov and an Anderson–Darling test on planets above and below this mass boundary, and find that they are two distinct populations. This could be additional evidence of two distinct populations possibly having two different formation pathways, with companion mass as an indicator of most likely formation scenario.
Abstract
Scattered light imaging of protoplanetary disks provides key insights on the geometry and dust properties in the disk surface. Here, we present James Webb Space Telescope (JWST) 2–21
μ
m ...images of a 1000 au radius edge-on protoplanetary disk surrounding an 0.4
M
⊙
young star in Taurus, Two Micron All Sky Survey (2MASS) J04202144 + 2813491. These observations represent the longest wavelengths at which a protoplanetary disk is spatially resolved in scattered light. We combine these observations with Hubble Space Telescope optical images and Atacama Large Millimeter/submillimeter Array continuum and CO mapping. We find that the changes in the scattered light disk morphology are remarkably small across a factor of 30 in wavelength, indicating that dust in the disk surface layers is characterized by an almost gray opacity law. Using radiative transfer models, we conclude that grains up to ≳10
μ
m in size are fully coupled to the gas in this system, whereas grains ≳100
μ
m are strongly settled toward the midplane. Further analyses of these observations, and similar ones of other edge-on disks, will provide strong empirical constraints on disk dynamics and evolution and grain growth models. In addition, the 7.7 and 12.
μ
m JWST images reveal an X-shaped feature located above the warm molecular layer traced by CO line emission. The highest elevations at which this feature is detectable roughly match the maximal extent of the disk in visible wavelength scattered light as well as of an unusual kinematic signature in CO. We propose that these phenomena could be related to a disk wind entraining small dust grains.
Abstract
We present James Webb Space Telescope imaging from 2 to 21
μ
m of the edge-on protoplanetary disk around the embedded young star IRAS04302+2247. The structure of the source shows two ...reflection nebulae separated by a dark lane. The source extent is dominated by the extended filamentary envelope at ∼4.4
μ
m and shorter wavelengths, transitioning at 7.7
μ
m and longer wavelengths to more compact lobes of scattered light from the disk itself. The dark lane thickness does not vary significantly with wavelength, which we interpret as an indication for intermediate-sized (∼10
μ
m) grains in the upper layers of the disk. Intriguingly, we find that the brightest nebula of IRAS40302 switches side between 12.8 and 21
μ
m. We explore the effect of a tilted inner region on the general appearance of edge-on disks. We find that radiative transfer models of a disk including a tilted inner region can reproduce an inversion in the brightest nebula. In addition, for specific orientations, the model predicts strong lateral asymmetries, which can occur for more than half possible viewing azimuths. A large number of edge-on protoplanetary disks observed in scattered light show such lateral asymmetries (15/20), which suggests that a large fraction of protoplanetary disks might host a tilted inner region. Stellar spots may also induce lateral asymmetries, which are expected to vary over a significantly shorter timescale. Variability studies of edge-on disks would allow us to test the dominant scenario for the origin of these asymmetries.
John of the Cross (1542-1591), a Christian theologian and Catholic priest born in Spain, lived through the worst of the Spanish Inquisition. Emmanuel Lévinas (1906-1995), a Jewish philosopher and ...layman born in Lithuania, lived through the 1917 Russian Revolution and the collapse of the old regime. What, then, brings these two eminent thinkers together: one from the upheavals of 16th-century Spain; the other from war-torn 20th-century France and Germany? Simply put, both of these men refused to start their reflection on life and God from self-contained abstract principles; rather, their point of departure was the ambiguity and complexity of the character of human nature. From this starting point, both are led to a God without or beyond Being. After a comparative analysis of their God talk, the following questions are explored: How do we speak about God? What are the consequences of John’s and Levinas’ radical negation of the Being of God?
Abstract
The structure of protoplanetary disks plays an essential role in planet formation. A disk that is highly inclined, or “edge-on,” is of particular interest since its geometry provides a ...unique opportunity to study the disk’s vertical structure and radial extent. Candidate edge-on protoplanetary disks are typically identified via their unique spectral energy distributions (SEDs) and subsequently confirmed through high-resolution imaging. However, this selection process is likely biased toward the largest, most-massive disks, and the resulting sample may not accurately represent the underlying disk population. To investigate this, we generated a grid of protoplanetary disk models using radiative transfer simulations and determined which sets of disk parameters produce edge-on systems that could be recovered by the aforementioned detection techniques—i.e., identified by their SEDs and confirmed through follow-up imaging with the Hubble Space Telescope. In doing so, we adopt a quantitative working definition of “edge-on disks” (EODs) that is observation driven and agnostic about the disk inclination or other properties. Folding in empirical disk demographics, we predict an occurrence rate of 6.2% for EODs and quantify biases toward highly inclined, massive disks. We also find that EODs are underrepresented in samples of Spitzer-studied young stellar objects, particularly for disks with host masses of
M
≲ 0.5
M
⊙
. Overall, our analysis suggests that several dozen EODs remain undiscovered in nearby star-forming regions, and provides a universal selection process to identify EODs for consistent, population-level demographic studies.
ABSTRACT We present the first images of four debris disks observed in scattered light around the young (4-250 Myr old) M dwarfs TWA 7 and TWA 25, the K6 star HD 35650, and the G2 star HD 377. We ...obtained these images by reprocessing archival Hubble Space Telescope NICMOS coronagraph data with modern post-processing techniques as part of the Archival Legacy Investigation of Circumstellar Environments program. All four disks appear faint and compact compared with other debris disks resolved in scattered light. The disks around TWA 25, HD 35650, and HD 377 appear very inclined, while TWA 7's disk is viewed nearly face-on. The surface brightness of HD 35650's disk is strongly asymmetric. These new detections raise the number of disks resolved in scattered light around M and late-K stars from one (the AU Mic system) to four. This new sample of resolved disks enables comparative studies of heretofore scarce debris disks around low-mass stars relative to solar-type stars.
Abstract
We present high-resolution
12
CO and
13
CO 2–1 ALMA observations, as well as optical and near-infrared spectroscopy, of the highly inclined protoplanetary disk around SSTC2D ...J163131.2–242627. The spectral type we derive for the source is consistent with a 1.2
M
⊙
star inferred from the ALMA observations. Despite its massive circumstellar disk, we find little to no evidence for ongoing accretion on the star. The CO maps reveal a disk that is unusually compact along the vertical direction, consistent with its appearance in scattered light images. The gas disk extends about twice as far away as both the submillimeter continuum and the optical scattered light. CO is detected from two surface layers separated by a midplane region in which CO emission is suppressed, as expected from freeze-out in the cold midplane. We apply a modified version of the tomographically reconstructed distribution method presented by Dutrey et al. to derive the temperature structure of the disk. We find a temperature in the CO-emitting layers and the midplane of ∼33 K and ∼20 K at
R
< 200 au, respectively. Outside of
R
> 200 au, the disk’s midplane temperature increases to ∼30 K, with a nearly vertically isothermal profile. The transition in CO temperature coincides with a dramatic reduction in the submicron and submillimeter emission from the disk. We interpret this as interstellar UV radiation providing an additional source of heating to the outer part of the disk.
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