Abstract
We present Gemini-NIFS, Very Large Telescope-SINFONI, and Keck-OSIRIS observations of near-IR Fe
ii
emission that are associated with well-studied jets from three active T Tauri stars—RW ...Aur A, RY Tau, and DG Tau—taken from 2012 to 2021. We primarily cover the redshifted jet from RW Aur A and the blueshifted jets from RY Tau and DG Tau, in order to investigate long-term time variabilities that are potentially related to the activities of mass accretion and/or the stellar magnetic fields. All of these jets consist of several moving knots, with tangential velocities of 70–240 km s
−1
, which were ejected from the star with different velocities and at irregular time intervals. Via comparisons with the literature, we identify significant differences in the tangential velocities between 1985–2008 and 2008–2021 for the DG Tau jet. The sizes of the individual knots appear to increase with time, and, in turn, their peak brightnesses in the 1.644
μ
m emission decreased by up to a factor of ∼30 during the epochs of our observations. The variety of decay timescales measured in the Fe
ii
1.644
μ
m emission could be attributed to different preshock conditions should the moving knots be unresolved shocks. However, our data do not exclude the possibility that these knots are due to nonuniform density/temperature distributions with another heating mechanism, or, in some cases, due to stationary shocks without proper motions. Spatially resolved observations of these knots with significantly higher angular resolutions will be necessary to better understand their physical nature.
Background Women are twice as likely as men to suffer from stress-related affective disorders. Corticotropin-releasing factor (CRF) is an important link between stress and mood, in part through its ...signaling in the serotonergic dorsal raphe (DR). Development of CRF receptor-1 (CRFr1) antagonists has been a focus of numerous clinical trials but has not yet been proven efficacious. We hypothesized that sex differences in CRFr1 modulation of DR circuits might be key determinants in predicting therapeutic responses and affective disorder vulnerability. Methods Male and female mice received DR infusions of the CRFr1 antagonist, NBI 35965, or CRF and were evaluated for stress responsivity. Sex differences in indices of neural activation (cFos) and colocalization of CRFr1 throughout the DR were examined. Whole-cell patch-clamp electrophysiology assessed sex differences in serotonin neuron membrane characteristics and responsivity to CRF. Results Males showed robust behavioral and hypothalamic-pituitary-adrenal axis responses to DR infusion of NBI 35965 and CRF, whereas females were minimally responsive. Sex differences were also found for both CRF-induced DR cFos and CRFr1 co-localization throughout the DR. Electrophysiologically, female serotonergic neurons showed blunted membrane excitability and divergent inhibitory postsynaptic current responses to CRF application. Conclusions These studies demonstrate convincing sex differences in CRFr1 activity in the DR, where blunted female responses to NBI 35965 and CRF suggest unique stress modulation of the DR. These sex differences might underlie affective disorder vulnerability and differential sensitivity to pharmacologic treatments developed to target the CRF system, thereby contributing to a current lack of CRFr1 antagonist efficacy in clinical trials.
We present a detailed study of the centre of NGC 4654, a Milky Way-like spiral galaxy in the Virgo cluster that has been reported to host a double stellar nucleus, thus promising a rare view of ...ongoing star cluster infall into a galaxy nucleus. Analysing JWST NIRSpec integral-field spectroscopic data in combination with Hubble Space Telescope Wide Field Camera 3 imaging of the inner 330 × 330 pc, we find that the NGC 4645 nucleus is in fact more complex than previously thought, harbouring three massive star clusters within 32 pc of the centre. Maps of infrared emission lines in the NIRSpec spectra show different morphologies for the ionised and molecular gas components. The emission from molecular hydrogen gas is concentrated at the nuclear star cluster (NSC) location, while emission from hydrogen recombination lines is more extended beyond the central cluster. The velocity fields of both gas and stars indicate that the three clusters are part of a complicated dynamical system, with the NSC having an elevated velocity dispersion in line with its high stellar mass. To investigate the stellar populations of the three clusters in more detail, we used surface brightness modelling to measure their fluxes from UV to mid-infrared wavelengths. This information, together with spectroscopically derived extinction values, are then used to fit the spectral energy distributions (SEDs) of the clusters. Two of the clusters are UV-bright and well described by single stellar populations with young ages (∼3 and 5 Myr) and relatively low masses ( M * ∼ 4 × 10 4 M ⊙ and M * ∼ 10 5 M ⊙ , respectively), whereas the central cluster is much more massive ( M * = 3 × 10 7 M ⊙ ), and cannot be fitted by a single stellar population. Instead, we find that the presence of a minor young population (∼1 Myr, M * ∼ 3 × 10 4 M ⊙ ) embedded in a dominant old population (∼8 Gyr) is required to explain its SED. Given its complex composition and the close proximity of two young star clusters that are likely to merge with it within a few hundred million years, we consider the nucleus of NGC 4654 a unique laboratory to study NSC growth from both in situ star formation and the infall of star clusters.
Monitoring Inner Regions in the RY Tau Jet Uyama, Taichi; Takami, Michihiro; Cugno, Gabriele ...
The Astronomical journal,
06/2022, Letnik:
163, Številka:
6
Journal Article
Recenzirano
Odprti dostop
Abstract
We present multiepoch observations of the RY Tau jet for H
α
and Fe
ii
1.644
μ
m emission lines obtained with the Subaru Coronagraphic Extreme-AO and Visible Aperture Masking Polarimetric ...Imager for Resolved Exoplanetary Structures (VAMPIRES), Gemini Near-infrared Integral Field Spectrograph, and Keck/OSIRIS in 2019–2021. These data show a series of four knots within 1″ consistent with the proper motion of ∼0.″3 yr
−1
, analogous to the jets associated with another few active T Tauri stars. However, the spatial intervals between the knots suggest the time intervals of the ejections of about 1.2, 0.7, and 0.7 yr, significantly shorter than those estimated for the other stars. These H
α
images contrast with the archival Very Large Telescope Spectro-Polarimetric High-contrast Exoplanet Research and Zurich IMaging POLarimeter (ZIMPOL) observations from 2015, which showed only a single knot-like feature at ∼0.″25. The difference between the 2015 and 2019–2021 epochs suggests an irregular ejection interval within the six-year range. Such variations of the jet ejection may be related to a short-term (<1 yr) variability of the mass accretion rate. We compared the peaks of the H
α
emissions with the ZIMPOL data taken in 2015, showing the brighter profile at the base (<0.″3) than the 2020–2021 VAMPIRES profiles due to time-variable mass ejection rates or the heating–cooling balance in the jet. The observed jet knot structures may be alternatively attributed to stationary shocks, but a higher angular resolution is required to confirm its detailed origin.
Despite overwhelming adoption of wearable fitness trackers (WFT), it is unclear if they affect physical activity (PA) engagement or PA motivation. We hypothesized that combining a WFT with an ...effective intervention, motivational interviewing (MI), would positively influence both motivation and PA. A 12-week randomized controlled trial was conducted in 40 adults who did not meet PA recommendations. The four conditions were: a PA education (Educational control, n = 10), a WFT (WFT, n = 10), bi-weekly MI sessions (MI, n = 10), or both interventions (WFT+, n = 10). Motivation and PA were measured through an online survey and actigraphy pre- and post-intervention. Both the WFT+ and MI groups improved autonomous forms and decreased controlled forms of motivation. They also had higher basic psychological needs scores when compared to the Education group post-intervention. We detected no changes in PA. High autonomous motivation at baseline predicted higher post-intervention PA in the WFT+ group but predicted lower post-intervention PA in the WFT group. Results suggests that MI alone or with a WFT can improve basic psychological needs and autonomous forms of motivation for PA, but not PA participation. Individual differences in motivation at baseline may moderate the effect of a WFT on PA. This study was registered at clinicaltrials.gov (NCT490014).
Although immune-checkpoint inhibitors (ICIs) have been a remarkable advancement in bladder cancer treatment, the response rate to single-agent ICIs remains suboptimal. There has been substantial ...interest in the use of epigenetic agents to enhance ICI efficacy, although precisely how these agents potentiate ICI response has not been fully elucidated. We identified entinostat, a selective HDAC1/3 inhibitor, as a potent antitumor agent in our immune-competent bladder cancer mouse models (BBN963 and BBN966). We demonstrate that entinostat selectively promoted immune editing of tumor neoantigens, effectively remodeling the tumor immune microenvironment, resulting in a robust antitumor response that was cell autonomous, dependent upon antigen presentation, and associated with increased numbers of neoantigen-specific T cells. Finally, combination treatment with anti-PD-1 and entinostat led to complete responses and conferred long-term immunologic memory. Our work defines a tumor cell-autonomous mechanism of action for entinostat and a strong preclinical rationale for the combined use of entinostat and PD-1 blockade in bladder cancer.
Abstract We present JWST MIRI MRS observations of the edge-on protoplanetary disk around the young subsolar-mass star Tau 042021, acquired as part of the Cycle 1 GO program “Mapping Inclined Disk ...Astrochemical Signatures.” These data resolve the mid-IR spatial distributions of H 2 , revealing X-shaped emission extending to ∼200 au above the disk midplane with a semiopening angle of 35° ± 5°. We do not velocity-resolve the gas in the spectral images, but the measured semiopening angle of the H 2 is consistent with a magnetohydrodynamic wind origin. A collimated, bipolar jet is seen in forbidden emission lines from Ne ii , Ne iii , Ni ii , Fe ii , Ar ii , and S iii . Extended H 2 O and CO emission lines are also detected, reaching diameters of ∼90 and 190 au, respectively. Hot molecular emission is not expected at such radii, and we interpret its extended spatial distribution as scattering of inner disk molecular emission by dust grains in the outer disk surface. H i recombination lines, characteristic of inner disk accretion shocks, are similarly extended and are likely also scattered light from the innermost star–disk interface. Finally, we detect extended polycyclic aromatic hydrocarbon (PAH) emission at 11.3 μ m cospatial with the scattered-light continuum, making this the first low-mass T Tauri star around which extended PAHs have been confirmed, to our knowledge. MIRI MRS line images of edge-on disks provide an unprecedented window into the outflow, accretion, and scattering processes within protoplanetary disks, allowing us to constrain the disk lifetimes and accretion and mass-loss mechanisms.
On the Nature of the T Tauri Triple System Beck, Tracy L.; Schaefer, G. H.; Guilloteau, S. ...
Astrophysical journal/The Astrophysical journal,
10/2020, Letnik:
902, Številka:
2
Journal Article
Recenzirano
Odprti dostop
We present a multiwavelength analysis to reveal the nature of the enigmatic T Tauri triple star system. New optical and infrared measurements are coupled with archival X-ray, UV, and millimeter data ...sets to show the morphologies of disk material and outflow kinematics. A dark lane of obscuring material is seen in silhouette in several emission lines and in model-subtracted ALMA millimeter continuum dust residuals near the position of T Tau Sa+Sb, revealing the attenuating circumbinary ring around T Tau S. The flux variability of T Tau S is linked in part to the binary orbit; T Tau Sb brightens near orbital apastron as it emerges from behind circumbinary material. Outflow diagnostics confirm that T Tau N powers the blueshifted western outflow, and the T Tau S binary drives the northwest-southeastern flow. Analysis of the southern outflow shows periodic arcs ejected from the T Tau system. Correlation of these arc locations and tangential kinematics with the orbit timing suggests that launch of the last four southern outflow ejections is contemporaneous with, and perhaps triggered by, the T Tau Sa+Sb binary periastron passage. We present a geometry of the T Tau triple that has the southern components foreground to T Tau N, obscured by a circumbinary ring, with misaligned disks and interacting outflows. Particularly, a wind from T Tauri Sa that is perpendicular to its circumstellar disk might interact with the circumbinary material, which may explain conflicting high-contrast measurements of the system outflows in the literature. T Tauri is an important laboratory for understanding early dynamical processes in young multiple systems. We discuss the historical and future characteristics of the system in this context.
Young accreting stars drive outflows that collimate into jets, which can be seen hundreds of au from their driving sources. Accretion and outflow activity cease with system age, and it is believed ...that magneto-centrifugally launched disk winds are critical agents in regulating accretion through the protoplanetary disk. Protostellar jets are well studied in classical T Tauri stars (
M
⋆
≲ 2
M
⊙
), while few nearby (
d
≲ 150 pc) intermediate-mass stars (
M
⋆
= 2−10
M
⊙
), known as Herbig Ae/Be stars, have detected jets. We report VLT/MUSE observations of the Herbig Ae/Be star HD 100546 and the discovery of a protostellar jet. The jet is similar in appearance to jets driven by low-mass stars and compares well with the jet of HD 163296, the only other known optical jet from a nearby Herbig Ae/Be star. We derive a (one-sided) mass-loss rate in the jet of log
Ṁ
jet
∼ −9.5 (in
M
⊙
yr
−1
) and a ratio of outflow to accretion of roughly 3 × 10
−3
, which is lower than that of CTTS jets. The discovery of the HD 100546 jet is particularly interesting because the protoplanetary disk around HD 100546 shows a large radial gap, spiral structure, and might host a protoplanetary system. A bar-like structure previously seen in H
α
with VLT/SPHERE shares the jet position angle, likely represents the base of the jet, and suggests a jet-launching region within about 2 au. We conclude that the evolution of the disk at radii beyond a few au does not affect the ability of the system to launch jets.
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