Abstract
The nearby, luminous infrared galaxy NGC 7469 hosts a Seyfert nucleus with a circumnuclear star-forming ring and is thus the ideal local laboratory for investigating the starburst–AGN ...(active galactic nucleus) connection in detail. We present integral-field observations of the central 1.3 kpc region in NGC 7469 obtained with the JWST Mid-InfraRed Instrument. Molecular and ionized gas distributions and kinematics at a resolution of ∼100 pc over the 4.9–7.6
μ
m region are examined to study the gas dynamics influenced by the central AGN. The low-ionization Fe
ii
λ
5.34
μ
m and Ar
ii
λ
6.99
μ
m lines are bright on the nucleus and in the starburst ring, as opposed to H
2
S(5)
λ
6.91
μ
m, which is strongly peaked at the center and surrounding ISM. The high-ionization Mg
v
line is resolved and shows a broad, blueshifted component associated with the outflow. It has a nearly face-on geometry that is strongly peaked on the nucleus, where it reaches a maximum velocity of −650 km s
−1
, and extends about 400 pc to the east. Regions of enhanced velocity dispersion in H
2
and Fe
ii
∼ 180 pc from the AGN that also show high
L
(H
2
)/
L
(PAH) and
L
(Fe
ii
)/
L
(Pf
α
) ratios to the W and N of the nucleus pinpoint regions where the ionized outflow is depositing energy, via shocks, into the dense interstellar medium between the nucleus and the starburst ring. These resolved mid-infrared observations of the nuclear gas dynamics demonstrate the power of JWST and its high-sensitivity integral-field spectroscopic capability to resolve feedback processes around supermassive black holes in the dusty cores of nearby luminous infrared galaxies.
The authors tested the hypothesis that fluoxetine, when used in combination with relapse prevention psychotherapy, directly reduces relapse frequency and severity for alcoholics.
The authors ...conducted a randomized, placebo-controlled trial of fluoxetine (up to a maximum of 60 mg/day) for 12 weeks in combination with weekly psychotherapy for 101 alcohol-dependent subjects who were not selected on the basis of comorbid major depression. Outcomes were measured at the end of treatment and 6 months after treatment.
Placebo-treated subjects were more complaint with the medication regimen and remained in the study longer than fluoxetine-treated subjects. There was significantly less alcohol consumption in both groups during treatment than before treatment. These effects persisted during the posttreatment period. Although fluoxetine treatment had no significant effects on alcohol consumption, it reduced Hamilton Depression Rating Scale scores more than placebo treatment among subjects with current major depression.
Fluoxetine at a dose of 60 mg/day is probably not of use for relapse prevention in alcoholics with mild to moderate alcohol dependence and no comorbid depression. In alcoholics with major depression, the drug may reduce depressive symptoms. Subsequent studies with fluoxetine should probably focus on more severely alcohol-dependent subjects or those with comorbid depression.
Northwest Africa 479 (NWA 479) is a lunar meteorite recovered in 2000 from Morocco. This unbrecciated low-Ti basalt is paired with NWA 032. The texture of NWA 032/479 indicates a simple ...crystallization history and a fast cooling, followed by an impact event. The occurrence of high-pressure polymorphs of olivine (ringwoodite and wadsleyite) in shock-melt veins indicates shock-pressures of at least 20 GPa.
Lithium abundances and isotopic compositions were measured by ion microprobe in pyroxene, olivine crystals, and magmatic inclusions. The δ
7Li values in the magmatic inclusions indicate that the NWA 479 parental melt was enriched in
7Li (δ
7Li = +15‰). The behavior of Li depicted by the phenocrysts is complex and is not controlled by their major element compositions. Li abundances and δ
7Li values range respectively from 3.2 to 11.8 μg/g and +2.4 to +15.1‰ in olivine and from 2.8 to 18.4 μg/g and −0.2 to + 16.1‰ in pyroxene phenocrysts. Neither hot desert weathering, closed-system fractional crystallization, involvement of a low-δ
7Li reservoir, degassing of NWA 479 parental melt, nor shock metamorphism correctly explain the Li distribution in the phenocrysts. We propose that the wide range of δ
7Li values displayed by the phenocrysts results from the large diffusivity differences between
6Li and
7Li. It is shown that this difference is able to produce large isotopic heterogeneities in a very short time.
Abstract
We present James Webb Space Telescope (JWST) Near Infrared Spectrograph (NIRSpec) integral field spectroscopy of the nearby luminous infrared galaxy NGC 7469. We take advantage of the high ...spatial/spectral resolution and wavelength coverage of JWST/NIRSpec to study the 3.3
μ
m neutral polycyclic aromatic hydrocarbon (PAH) grain emission on ∼200 pc scales. A clear change in the average grain properties between the star-forming ring and the central AGN is found. Regions in the vicinity of the AGN, with Ne
iii
/Ne
ii
> 0.25, tend to have larger grain sizes and lower aliphatic-to-aromatic (3.4/3.3) ratios, indicating that smaller grains are preferentially removed by photodestruction in the vicinity of the AGN. PAH emission at the nucleus is weak and shows a low 11.3/3.3 PAH ratio. We find an overall suppression of the total PAH emission relative to the ionized gas in the central 1 kpc region of the AGN in NGC 7469 compared to what has been observed with Spitzer on 3 kpc scales. However, the fractional 3.3
μ
m–to–total PAH power is enhanced in the starburst ring, possibly due to a variety of physical effects on subkiloparsec scales, including recurrent fluorescence of small grains or multiple photon absorption by large grains. Finally, the IFU data show that while the 3.3
μ
m PAH-derived star formation rate (SFR) in the ring is 27% higher than that inferred from the Ne
ii
and Ne
iii
emission lines, the integrated SFR derived from the 3.3
μ
m feature would be underestimated by a factor of 2 due to the deficit of PAHs around the AGN, as might occur if a composite system like NGC 7469 were to be observed at high redshift.
Abstract
We have used the Mid-InfraRed Instrument (MIRI) on the James Webb Space Telescope (JWST) to obtain the first spatially resolved, mid-infrared images of
IIZw096
, a merging luminous infrared ...galaxy (LIRG) at
z
= 0.036. Previous observations with the Spitzer Space Telescope suggested that the vast majority of the total IR luminosity (
L
IR
) of the system originated from a small region outside of the two merging nuclei. New observations with JWST/MIRI now allow an accurate measurement of the location and luminosity density of the source that is responsible for the bulk of the IR emission. We estimate that 40%–70% of the IR bolometric luminosity, or 3–5 × 10
11
L
⊙
, arises from a source no larger than 175 pc in radius, suggesting a luminosity density of at least 3–5 × 10
12
L
⊙
kpc
−2
. In addition, we detect 11 other star-forming sources, five of which were previously unknown. The MIRI F1500W/F560W colors of most of these sources, including the source responsible for the bulk of the far-IR emission, are much redder than the nuclei of local LIRGs. These observations reveal the power of JWST to disentangle the complex regions at the hearts of merging, dusty galaxies.
Context. Direct imaging of exoplanets is a challenging task that requires state-of-the-art instrumentation and advanced image-processing techniques. Differential imaging techniques have proven useful ...for the detection of exoplanet companions around stars. Angular differential imaging (ADI) and spectral differential imaging (SDI) are commonly used for direct detection and characterisation of young, Jovian exoplanets in datasets obtained with the SPHERE/IFS instrument. Aims. We compare the performance of ADI, SDI, and three combinations of ADI and SDI to find which technique achieves the highest signal-to-noise ratio (S/N), and we analyse their performance as functions of integration time, field rotation, and wavelength range. Methods. We analyse SPHERE/IFS observations of three known exoplanets, namely β Pictoris b, 51 Eridani b, and HR 8799 e, with five differential imaging techniques. We split the datasets into subsets to vary each parameter before the data are processed with each technique. The differential imaging techniques are applied using principal component analysis (PCA). Results. The tests show that a combination of SDI and ADI consistently achieves better results than ADI alone, and using SDI and ADI simultaneously (combined differential imaging; CODI) achieved the best results. The integration time test shows that targets with a separation larger than 0.24 arcsec observed with an integration time of more than 103 s were photon-noise limited. Field rotation shows a strong correlation with S/N for field rotations up to 1 full width at half maximum (FWHM), after which no significant increase in S/N with field rotation is observed. Wavelength range variation shows a general increase in S/N for broader wavelength ranges, but no clear correlation is seen. Conclusions. Spectral information is essential to boost S/N compared to regular ADI. Our results suggest that CODI should be the preferred processing technique to search for new exoplanets with SPHERE/IFS. To optimise direct-imaging observations, the field rotation should exceed 1 FWHM to detect exoplanets at small separations.
Abstract We present new JWST NIRSpec integral field spectroscopy (IFS) data for the luminous infrared galaxy NGC 7469, a nearby (70.6 Mpc) active galaxy with a Seyfert 1.5 nucleus that drives a ...highly ionized gas outflow and a prominent nuclear star-forming ring. Using the superb sensitivity and high spatial resolution of the JWST instrument NIRSpec IFS, we investigate the role of the Seyfert nucleus in the excitation and dynamics of the circumnuclear gas. Our analysis focuses on the Fe ii , H 2 , and hydrogen recombination lines that trace the radiation/shocked-excited molecular and ionized interstellar medium around the active galactic nucleus (AGN). We investigate gas excitation through H 2 /Br γ and Fe ii /Pa β emission line ratios and find that photoionization by the AGN dominates within the central 300 pc of the galaxy except in a small region that shows signatures of shock-heated gas; these shock-heated regions are likely associated with a compact radio jet. In addition, the velocity field and velocity dispersion maps reveal complex gas kinematics. Rotation is the dominant feature, but we also identify noncircular motions consistent with gas inflows as traced by the velocity residuals and the spiral pattern in the Pa α velocity dispersion map. The inflow is 2 orders of magnitude higher than the AGN accretion rate. The compact nuclear radio jet has enough power to drive the highly ionized outflow. This scenario suggests that the inflow and outflow are in a self-regulating feeding–feedback process, with a contribution from the radio jet helping to drive the outflow.
We report on the petrology and chemistry of North West Africa 1068 (NWA 1068), a shergottite recently recovered in Morocco. This meteorite has a total known mass of about 577 g and comprises 23 ...fragments. The largest fragment is a greenish-brown rock devoid of fusion crust. It displays a porphyritic texture consisting of a fine-grained groundmass and olivine grains. Excluding the impact melt pockets and the minor carbonate veins produced by terrestrial weathering, modal analyses indicate the following mineral proportions: 52 vol% pyroxenes, 22% maskelynite, 21% olivine, 2% phosphates (merrillite and chlorapatite), 2% opaque oxides (mainly ilmenite and chromite) and sulfides, and 1% K-rich mesostasis. Olivines with various habits occur as clusters often associated with chromite, or single crystals ranging in size from 50 μm to 2 millimeters (“megacrysts”). These crystals originate probably from disrupted cumulates with strong affinities with peridotitic shergottites.
The bulk composition of NWA 1068 has been determined for 45 elements. It is an Al-poor ferroan basaltic rock, rich in MgO. Its major element composition is similar to those reported for other picritic shergottites, especially EETA79001A. Furthermore, key element ratios such as Fe/Mn (45), Al/Ti (6.6), Na/Ti (1.83), Ga/Al (4.4 × 10
−4) and Na/Al (0.28) are typical of Martian meteorites. The trace elements demonstrate unambiguously that NWA 1068 is unpaired with any of the other hot desert finds: it is the first picritic shergottite with a REE pattern similar to those of Shergotty, Zagami, and Los Angeles.
Incompatible element abundances indicate that NWA 1068 was not formed from a “primitive” shergottitic melt. It derived more likely from a basaltic shergottite, which has accumulated (and possibly partly digested) fragments of an olivine-rich lithology, in full agreement with major element abundances and petrographical interpretations.
Abstract
We present mid-infrared spectroscopic observations of the nucleus of the nearby Seyfert galaxy NGC 7469 taken with the MIRI instrument on the James Webb Space Telescope (JWST) as part of ...Directors Discretionary Time Early Release Science program 1328. The high-resolution nuclear spectrum contains 19 emission lines covering a wide range of ionization. The high-ionization lines show broad, blueshifted emission reaching velocities up to 1700 km s
−1
and FWHM ranging from ∼500 to 1100 km s
−1
. The width of the broad emission and the broad-to-narrow line flux ratios correlate with ionization potential. The results suggest a decelerating, stratified, AGN-driven outflow emerging from the nucleus. The estimated mass outflow rate is 1–2 orders of magnitude larger than the current black hole accretion rate needed to power the AGN. Eight pure rotational H
2
emission lines are detected with intrinsic widths ranging from FWHM ∼125 to 330 km s
−1
. We estimate a total mass of warm H
2
gas of ∼1.2 × 10
7
M
⊙
in the central 100 pc. The PAH features are extremely weak in the nuclear spectrum, but a 6.2
μ
m PAH feature with an equivalent width of ∼0.07
μ
m and a flux of 2.7 × 10
−17
W m
−2
is detected. The spectrum is steeply rising in the mid-infrared, with a silicate strength of ∼0.02, significantly smaller than seen in most PG QSOs but comparable to other Seyfert 1s. These early MIRI mid-infrared IFU data highlight the power of JWST to probe the multiphase interstellar media surrounding actively accreting supermassive black holes.
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