69 research outputs found

    Strong Lensing Analysis of A1689 from Deep Advanced Camera Images

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    We analyse deep multi-colour Advanced Camera images of the largest known gravitational lens, A1689. Radial and tangential arcs delineate the critical curves in unprecedented detail and many small counter-images are found near the center of mass. We construct a flexible light deflection field to predict the appearance and positions of counter-images. The model is refined as new counter-images are identified and incorporated to improve the model, yielding a total of 106 images of 30 multiply lensed background galaxies, spanning a wide redshift range, 1.0<<z<<5.5. The resulting mass map is more circular in projection than the clumpy distribution of cluster galaxies and the light is more concentrated than the mass within r<50kpc/hr<50kpc/h. The projected mass profile flattens steadily towards the center with a shallow mean slope of dlog⁥Σ/dlog⁥r≃−0.55±0.1d\log\Sigma/d\log r \simeq -0.55\pm0.1, over the observed range, r<250kpc/h<250kpc/h, matching well an NFW profile, but with a relatively high concentration, Cvir=8.2−1.8+2.1C_{vir}=8.2^{+2.1}_{-1.8}. A softened isothermal profile (rcore=20±2r_{core}=20\pm2\arcs) is not conclusively excluded, illustrating that lensing constrains only projected quantities. Regarding cosmology, we clearly detect the purely geometric increase of bend-angles with redshift. The dependence on the cosmological parameters is weak due to the proximity of A1689, z=0.18z=0.18, constraining the locus, ΩM+ΩΛ≀1.2\Omega_M+\Omega_{\Lambda} \leq 1.2. This consistency with standard cosmology provides independent support for our model, because the redshift information is not required to derive an accurate mass map. Similarly, the relative fluxes of the multiple images are reproduced well by our best fitting lens model.Comment: Accepted by ApJ. For high quality figures see http://wise-obs.tau.ac.il/~kerens/A168

    The relationship between self-reported borderline personality features and prospective illness course in bipolar disorder

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    Abstract Background Although bipolar disorder (BD) and borderline personality disorder (BPD) share clinical characteristics and frequently co-occur, their interrelationship is controversial. Especially, the differentiation of rapid cycling BD and BPD can be troublesome. This study investigates the relationship between borderline personality features (BPF) and prospective illness course in patients with BD, and explores the effects of current mood state on self-reported BPF profiles. Methods The study included 375 patients who participated in the former Stanley Foundation Bipolar Network. All patients met DSM-IV criteria for bipolar-I disorder (n = 294), bipolar-II disorder (n = 72) or bipolar disorder NOS (n = 9). BPF were assessed with the self-rated Personality Diagnostic Questionnaire. Illness course was based on 1-year clinician rated prospective daily mood ratings with the life chart methodology. Regression analyses were used to estimate the relationships among these variables. Results Although correlations were weak, results showed that having more BPF at baseline is associated with a higher episode frequency during subsequent 1-year follow-up. Of the nine BPF, affective instability, impulsivity, and self-mutilation/suicidality showed a relationship to full-duration as well as brief episode frequency. In contrast all other BPF were not related to episode frequency. Conclusions Having more BPF was associated with an unfavorable illness course of BD. Affective instability, impulsivity, and self-mutilation/suicidality are associated with both rapid cycling BD and BPD. Still, many core features of BPD show no relationship to rapid cycling BD and can help in the differential diagnosis

    High-Redshift Galaxy Candidates at z=9−13z = 9-13 as Revealed by JWST Observations of WHL0137-08

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    JWST was designed to peer into the distant universe and study galaxies nearer the beginning of time than previously. Here we report the discovery of 12 galaxy candidates observed 300-600 Myr after the Big Bang with photometric redshifts between z ~ 8.5-13 measured using JWST NIRCam imaging of the galaxy cluster WHL0137 observed in 8 filters spanning 0.8-5.0 ÎŒ\mum, plus 9 HST filters spanning 0.4-1.7 ÎŒ\mum. Three of these candidates are gravitationally lensed by the foreground galaxy cluster and have magnifications of Ό∌3−8\mu \sim 3 - 8. The remaining nine candidates are located in a second JWST NIRCam module, centered ~29' from the cluster center, with expected magnifications of ÎŒ\mu <~ 1.1. Our sample of high-redshift candidates have observed F200W AB magnitudes between 25.9 and 28.1 mag and intrinsic F200W AB magnitudes between 26.4 and 29.7 mag (MUVM_{UV} = -22.5 to -17). We find the stellar masses of these galaxies are in the range log⁥M∗/M⊙\log M_{*}/M_{\odot} = 8 - 9, and down to 7.5 for the lensed galaxies. All are young with mass-weighted ages < 100 Myr, low dust content AVA_V < 0.15 mag, and high specific star formation rates sSFR ~10-50 Gyr−1^{-1} for most. One z ~ 9 candidate is consistent with an age < 5 Myr and a sSFR ~250 Gyr−1^{-1}, as inferred from a strong F444W excess, implying [OIII]+H-beta rest-frame equivalent width ~2000 Angstrom, although an older and redder z~ 10 object is also allowed. Another z~9 candidate ID9356 is lensed into an arc 2.6" long by the effects of strong gravitational lensing (ÎŒ\mu~8), and has at least two bright knots of unevenly distributed star formation. This arc is the most spatially-resolved galaxy at z~9 known to date, revealing structures ~30 pc across. Follow-up spectroscopy of WHL0137 with JWST/NIRSpec is planned for later this year, which will validate some of these candidates and study their physical properties in more detail.Comment: submitted to Ap

    Reaching for the stars – JWST/NIRSpec spectroscopy of a lensed star candidate at z = 4.76

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    We present JWST/NIRSpec observations of a highly magnified star candidate at a photometric redshift of zphot ≃ 4.8, previously detected in JWST/NIRCam imaging of the strong lensing (SL) cluster MACS J0647+7015 (z = 0.591). The spectroscopic observation allows us to precisely measure the redshift of the host arc at zspec = 4.758 ± 0.004, and the star’s spectrum displays clear Lyman- and Balmer-breaks commensurate with this redshift. A fit to the spectrum suggests a B-type super-giant star of surface temperature  K with either a redder F-type companion (⁠ K) or significant dust attenuation (AV ≃ 0.82) along the line of sight. We also investigate the possibility that this object is a magnified young globular cluster rather than a single star. We show that the spectrum is in principle consistent with a star cluster, which could also accommodate the lack of flux variability between the two epochs. However, the lack of a counter image and the strong upper limit on the size of the object from lensing symmetry, r â‰Č 0.5 pc, could indicate that this scenario is somewhat less likely – albeit not completely ruled out by the current data. The presented spectrum seen at a time when the Universe was only ∌1.2 Gyr old showcases the ability of JWST to study early stars through extreme lensing

    Reaching for the stars -- JWST/NIRSpec spectroscopy of a lensed star candidate at z=4.76z=4.76

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    We present JWST/NIRSpec observations of a highly magnified star candidate at a photometric redshift of zphot≃4.8z_{\mathrm{phot}}\simeq4.8, previously detected in JWST/NIRCam imaging of the strong lensing (SL) cluster MACS J0647+7015 (z=0.591z=0.591). The spectroscopic observation allows us to precisely measure the redshift of the host arc at zspec=4.758±0.004z_{\mathrm{spec}}=4.758\pm0.004, and the star's spectrum displays clear Lyman- and Balmer-breaks commensurate with this redshift. A fit to the spectrum suggests a B-type super-giant star of surface temperature Teff,B≃15000T_{\mathrm{eff,B}}\simeq15000 K with either a redder F-type companion (Teff,F≃6250T_{\mathrm{eff,F}}\simeq6250K) or significant dust attenuation (AV≃0.82A_V\simeq0.82) along the line of sight. We also investigate the possibility that this object is a magnified young globular cluster rather than a single star. We show that the spectrum is in principle consistent with a star cluster, which could also accommodate the lack of flux variability between the two epochs. However, the lack of a counter image and the strong upper limit on the size of the object from lensing symmetry, râ‰Č0.5r\lesssim0.5 pc, could indicate that this scenario is somewhat less likely -- albeit not completely ruled out by the current data. The presented spectrum seen at a time when the Universe was only ∌1.2\sim1.2 Gyr old showcases the ability of JWST to study early stars through extreme lensing.Comment: Accepted for publication in MNRAS letters. v2 updated to match the published versio

    JWST reveals a possible z∌11z \sim 11 galaxy merger in triply-lensed MACS0647−-JD

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    MACS0647−-JD is a triply-lensed z∌11z\sim11 galaxy originally discovered with the Hubble Space Telescope. Here we report new JWST imaging, which clearly resolves MACS0647−-JD as having two components that are either merging galaxies or stellar complexes within a single galaxy. Both are very small, with stellar masses ∌108 M⊙\sim10^8\,M_\odot and radii r<100 pcr<100\,\rm pc. The brighter larger component "A" is intrinsically very blue (ÎČ∌−2.6\beta\sim-2.6), likely due to very recent star formation and no dust, and is spatially extended with an effective radius ∌70 pc\sim70\,\rm pc. The smaller component "B" appears redder (ÎČ∌−2\beta\sim-2), likely because it is older (100−200 Myr100-200\,\rm Myr) with mild dust extinction (AV∌0.1 magA_V\sim0.1\,\rm mag), and a smaller radius ∌20 pc\sim20\,\rm pc. We identify galaxies with similar colors in a high-redshift simulation, finding their star formation histories to be out of phase. With an estimated stellar mass ratio of roughly 2:1 and physical projected separation ∌400 pc\sim400\,\rm pc, we may be witnessing a galaxy merger 400 million years after the Big Bang. We also identify a candidate companion galaxy C ∌3 kpc\sim3\,{\rm kpc} away, likely destined to merge with galaxies A and B. The combined light from galaxies A+B is magnified by factors of ∌\sim8, 5, and 2 in three lensed images JD1, 2, and 3 with F356W fluxes ∌322\sim322, 203203, 86 nJy86\,\rm nJy (AB mag 25.1, 25.6, 26.6). MACS0647−-JD is significantly brighter than other galaxies recently discovered at similar redshifts with JWST. Without magnification, it would have AB mag 27.3 (MUV=−20.4M_{UV}=-20.4). With a high confidence level, we obtain a photometric redshift of z=10.6±0.3z=10.6\pm0.3 based on photometry measured in 6 NIRCam filters spanning 1−5ÎŒm1-5\rm\mu m, out to 4300 A˚4300\,\r{A} rest-frame. JWST NIRSpec observations planned for January 2023 will deliver a spectroscopic redshift and a more detailed study of the physical properties of MACS0647−-JD.Comment: 27 pages, 14 figures, submitted to Natur

    Inflation and Dark Energy from spectroscopy at z &gt; 2

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    The genomic landscape of balanced cytogenetic abnormalities associated with human congenital anomalies

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    Despite the clinical significance of balanced chromosomal abnormalities (BCAs), their characterization has largely been restricted to cytogenetic resolution. We explored the landscape of BCAs at nucleotide resolution in 273 subjects with a spectrum of congenital anomalies. Whole-genome sequencing revised 93% of karyotypes and demonstrated complexity that was cryptic to karyotyping in 21% of BCAs, highlighting the limitations of conventional cytogenetic approaches. At least 33.9% of BCAs resulted in gene disruption that likely contributed to the developmental phenotype, 5.2% were associated with pathogenic genomic imbalances, and 7.3% disrupted topologically associated domains (TADs) encompassing known syndromic loci. Remarkably, BCA breakpoints in eight subjects altered a single TAD encompassing MEF2C, a known driver of 5q14.3 microdeletion syndrome, resulting in decreased MEF2C expression. We propose that sequence-level resolution dramatically improves prediction of clinical outcomes for balanced rearrangements and provides insight into new pathogenic mechanisms, such as altered regulation due to changes in chromosome topology

    Shared genetic risk between eating disorder- and substance-use-related phenotypes:Evidence from genome-wide association studies

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    First published: 16 February 202
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