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This narrative contains the MAG Analysis from: Clifton P Bueno de Mesquita, Wyatt H Hartman, Marcelo Ardón, Susannah G Tringe, Disentangling the effects of sulfate and other seawater ions on microbial communities and greenhouse gas emissions in a coastal forested wetland, ISME Communications, 2024; ycae040, https://doi.org/10.1093/ismeco/ycae040 Metagenomes were uploaded to IMG/M for other analyses.
This Narrative is part of a collection used in publications focused on the microbial ecology of fjord sediment in the high Arctic, Svalbard. This paper took a genome-centric approach to uncover novel metabolic capabilities of the Acidobacteriota clade. Metagenomic data was coupled with amplicon sequencing of 16S rRNA and dissimilatory sulfite reductase (dsrB) genes, and transcripts (available under NCBI-Genbank Bioproject PRJNA623111), and gene expression analyses of tetrathionate-amended microcosms. This Narrative contains the metagenomic assemblies that were constructed within KBase for reproducibility. These include: stnF metagenome assembly stnAB metagenome assembly stnAC metagenome assembly These metagenome assemblies served as the launching point for an additional publication focused on a different clade of bacteria (Buongiorno et al., 2020). Link to that Narrative landing page here. Please cite: Flieder, Mathias, Joy Buongiorno, Craig W. Herbold, Bela Hausmann, Thomas Rattei, Karen G. Lloyd, Alexander Loy, and Kenneth Wasmund. "Novel taxa of Acidobacteriota implicated in seafloor sulfur cycling." The ISME Journal (2021): 1-22.
The integrity of the final printed components is mostly dictated by the adhesion between the particles and phases that form upon solidification, which is a major problem in printing metallic parts using available In-Space Manufacturing (ISM) technologies based on the Fused Deposition Modeling (FDM) methodology. Understanding the melting/solidification process helps increase particle adherence and allows to produce components with greater mechanical integrity. We developed a phase-field model of solidification for binary alloys. The phase-field approach is unique in capturing the microstructure with computationally tractable costs. The developed phase-field model of solidification of binary alloys satisfies the stability conditions at all temperatures. The suggested model is tuned for Ni-Cu alloy feedstocks. We derived the Ginzburg-Landau equations governing the phase transformation kinetics and solved them analytically for the dilute solution. We calculated the concentration profile as a function of interface velocity for a one-dimensional steady-state diffuse interface neglecting elasticity and obtained the partition coefficient, k, as a function of interface velocity. Numerical simulations for the diluted solution are used to study the interface velocity as a function of undercooling for the classic sharp interface model, partitionless solidification, and thin interface.
GJ 9827 is a bright star hosting a planetary system with three transiting planets. As a multiplanet system with planets that sprawl within the boundaries of the radius gap between terrestrial and gaseous planets, GJ 9827 is an optimal target to study the evolution of the atmospheres of close-in planets with a common evolutionary history and their dependence from stellar irradiation. Here we report on the Hubble Space Telescope (HST) and CARMENES transit observations of GJ 9827 planets b and d. We performed a stellar and ISM characterization from the ultraviolet HST spectra, obtaining fluxes for Lyα and Mg ii of F(Lyα) = (5.42{sub −0.75}{sup +0.96}) × 10{sup −13} erg cm{sup −2} s{sup −1} and F(Mgii) = (5.64 ± 0.24) × 10{sup −14} erg cm{sup −2} s{sup −1}. We also investigated a possible absorption signature in Lyα in the atmosphere of GJ 9827b during a transit event from HST spectra, as well as Hα and He i signature for the atmosphere of GJ 9827b and d from CARMENES spectra. We found no evidence of an extended atmosphere in either of the planets. This result is also supported by our analytical estimations of mass loss based on the measured radiation fields for all three planets of this system, which led to a mass-loss rate of 0.4, 0.3, and 0.1 planetary masses per Gyr for GJ 9827b, c, and d, respectively. These values indicate that the planets could have lost their volatiles quickly in their evolution and probably do not retain an atmosphere at the current stage.
We report the results of analyses of galactic outflows in a sample of 45 low-redshift starburst galaxies in the COS Legacy Archive Spectroscopic SurveY (CLASSY), augmented by five additional similar starbursts with Cosmic Origins Spectrograph (COS) data. The outflows are traced by blueshifted absorption lines of metals spanning a wide range of ionization potential. The high quality and broad spectral coverage of CLASSY data enable us to disentangle the absorption due to the static interstellar medium (ISM) from that due to outflows. We further use different line multiplets and doublets to determine the covering fraction, column density, and ionization state as a function of velocity for each outflow. We measure the outflow's mean velocity and velocity width, and find that both correlate in a highly significant way with the star formation rate, galaxy mass, and circular velocity over ranges of four orders of magnitude for the first two properties. We also estimate outflow rates of metals, mass, momentum, and kinetic energy. We find that, at most, only about 20% of silicon created and ejected by supernovae in the starburst is carried out in the warm phase we observe. The outflows' mass-loading factor increases steeply and inversely with both circular and outflow velocity (log–log slope ~–1.6), and reaches ~10 for dwarf galaxies. We find that the outflows typically carry about 10%–100% of the momentum injected by massive stars and about 1%–20% of the kinetic energy. We show that these results place interesting constraints on, and new insights into, models and simulations of galactic winds.
We report on VLT/FORS2 imaging polarimetry observations in the R Special band of WISE J011601.41–050504.0 (W0116–0505), a heavily obscured hyperluminous quasar at z = 3.173 classified as a Hot Dust-obscured Galaxy (Hot DOG) based on its mid-IR colors. Recently, Assef et al. identified W0116–0505 as having excess rest-frame optical/UV emission and concluded that this excess emission is most likely scattered light from the heavily obscured AGN. We find that the broadband rest-frame UV flux is strongly linearly polarized (10.8% ± 1.9%, with a polarization angle of 74° ± 9°), confirming this conclusion. We analyze these observations in the context of a simple model based on scattering either by free electrons or by optically thin dust, assuming a classical dust torus with polar openings. Both can replicate the degree of polarization and the luminosity of the scattered component for a range of geometries and column densities, but we argue that optically thin dust in the ISM is the more likely scenario. We also explore the possibility that the scattering medium corresponds to an outflow recently identified for W0116–0505. This is a feasible option if the outflow component is biconical with most of the scattering occurring at the base of the receding outflow. In this scenario, the quasar would still be obscured even if viewed face-on but might appear as a reddened type 1 quasar once the outflow has expanded. We discuss a possible connection between blue-excess Hot DOGs, extremely red quasars, reddened type 1 quasars, and unreddened quasars that depends on a combination of evolution and viewing geometry.
Gamma-ray bursts (GRBs) are extremely high-energy events that can be observed at very high redshift. In addition to γ rays, they can emit in X-ray, optical, and sometimes radio wavelengths. Here, following the approach in Srinivasaragavan et al.; Dainotti et al.; and Dainotti et al., we consider 82 GRBs from Dainotti et al. that have been observed in optical wavelengths and fitted with a broken power law. We consider the relations between the spectral and temporal indices (closure relations; CRs) according to the synchrotron forward-shock model evolving in the constant-density interstellar medium (ISM; k = 0) and the stellar wind environment (k = 2) in both slow- and fast-cooling regimes, where the density profile is defined as n ∝ r -k . We find the $ν$ > $max${$ν$ c , $ν$ m } regime is most favored, where ν c and ν m are the cooling and characteristic frequencies, respectively. Finally, we test the 2D Dainotti correlation between the rest-frame end time of the plateau and the luminosity at that time on GRBs that fulfill the most-favored CRs. When we compare the intrinsic scatter σ int of those 2D correlations to the scatter presented in Dainotti et al., we see the scatters of our correlations generally agree with the previous values within 1σ, both before and after correction for selection bias. This new information has helped us to pinpoint subsamples of GRBs with features that could drive the GRB emission mechanism, and eventually allow for GRBs to be used as standard candles.
We investigate the relationships between the cool circumgalactic medium (CGM), traced by Ca II absorption lines, and galaxy properties at z < 0.4 using ∼900,000 galaxy–quasar pairs within 200 kpc from the Year 1 data of the Dark Energy Spectroscopic Instrument (DESI). This large data set enables us to obtain composite spectra with sensitivity reaching to the mÅ level and to explore the Ca II absorption as a function of stellar mass, star formation rate (SFR), redshift, and galaxy types, including active galactic nuclei (AGNs). Our results show a positive correlation between the absorption strength and stellar mass of star-forming galaxies with $\langle$$W$$^{Ca II}_{0}$$\rangle$ α $M$$^{0.5}_{*}$ over 3 orders of magnitude in stellar mass from ∼10 8 to 10 11 M ⊙ , while such a mass dependence is weaker for quiescent galaxies. At a fixed mass, Ca II absorption is stronger around star-forming galaxies than quiescent ones especially within impact parameters <30 kpc. Among star-forming galaxies, the Ca II absorption further correlates with SFR, following ∝SFR 0.3 . However, in contrast to the results at higher redshifts, stronger absorption is not preferentially observed along the minor axis of star-forming galaxies, indicating a possible redshift evolution of CGM dynamics resulting from galactic feedback. Moreover, no significant difference between the properties of the cool gas around AGNs and galaxies is detected. Finally, we measure the absorption profiles with respect to the virial radius of dark matter halos and show that the total Ca II mass in the CGM is comparable to the Ca mass in the ISM of galaxies.
We present initial results from a James Webb Space Telescope (JWST) survey of the youngest Galactic core-collapse supernova remnant, Cassiopeia A (Cas A), made up of NIRCam and MIRI imaging mosaics that map emission from the main shell, interior, and surrounding circumstellar/interstellar material (CSM/ISM). We also present four exploratory positions of MIRI Medium Resolution Spectrograph integral field unit spectroscopy that sample ejecta, CSM, and associated dust from representative shocked and unshocked regions. Surprising discoveries include (1) a weblike network of unshocked ejecta filaments resolved to ~0.01 pc scales exhibiting an overall morphology consistent with turbulent mixing of cool, low-entropy matter from the progenitor's oxygen layer with hot, high-entropy matter heated by neutrino interactions and radioactivity; (2) a thick sheet of dust-dominated emission from shocked CSM seen in projection toward the remnant's interior pockmarked with small (~1'') round holes formed by ≲0$^"_•$1 knots of high-velocity ejecta that have pierced through the CSM and driven expanding tangential shocks; and (3) dozens of light echoes with angular sizes between ~0$^"_•$1 and 1' reflecting previously unseen fine-scale structure in the ISM. NIRCam observations place new upper limits on infrared emission (≲20 nJy at 3 μm) from the neutron star in Cas A's center and tightly constrain scenarios involving a possible fallback disk. These JWST survey data and initial findings help address unresolved questions about massive star explosions that have broad implications for the formation and evolution of stellar populations, the metal and dust enrichment of galaxies, and the origin of compact remnant objects.
Abstract We report evidence of a hidden black hole (BH) in a low-mass galaxy, MaNGA 9885-9102, and provide a new method to identify active BHs in low-mass galaxies. This galaxy is originally selected from the MaNGA survey with distinctive bipolar Hαblobs at the minor axis. The bipolar feature can be associated with active galactic nuclei (AGN) activity, while the two blobs are classified as the Hiiregions on the BPT diagram, making the origins confusing. The Swift UV continuum shows that the two blobs do not have UV counterparts, suggesting that the source of ionization is out of the blobs. Consistent with this, the detailed photoionization models prefer AGN rather than the star-forming origin with a significance of 5.8σ. The estimated BH mass isM BH ∼ 7.2 × 10 5 M ⊙ from theM BH –σ * relationship. This work introduces a novel method for detecting the light echo of BHs, potentially extending to intermediate mass, in low-metallicity environments where the traditional BPT diagram fails.
Abstract In the last decade, there have been several discoveries of active galactic nuclei (AGN) in dwarf galaxies including an AGN in an ultracompact dwarf galaxy with a black hole mass >10 6 M ⊙ . However, finding a supermassive black hole (SMBH) in a dwarf low surface brightness (LSB) galaxy is rare. We report the discovery of a Seyfert type 2 class AGN that is associated with a nuclear SMBH of mass ∼6.5 × 10 6 M ⊙ in a dwarf LSB galaxy (μ 0,r > 23.8 mag arcsec −2 ) that we denote by MJ0818+2257. The galaxy was previously thought to be an outlying emission blob around the large spiral galaxy LEDA 1678924. In our current analysis, which includes the detection of the optical counterpart of MJ0818+2257, we study its ionized gas kinematics and find that the dynamical mass within the ionized gas disk is ∼5.3 × 10 9 M ⊙ . This is comparable to its stellar mass, which is ∼3 × 10 9 M ⊙ , and suggests that MJ0818+2257 is moderately dark matter dominated within the stellar disk. The SMBH-mass-to-galaxy-stellar-mass ratio isM BH /M(*) > 0.022, which is high compared to disk galaxies. Our detection of an SMBH in a bulgeless LSB dwarf galaxy raises questions about the growth of SMBHs in low-luminosity galaxies and suggests the possibility of detecting heavy seed black holes from early epochs in LSB dwarf galaxies in the low-redshift Universe.
This panel focused on the what the Department of Energy (DOE) and its contractors are doing to promote safety and excellence. The Integrated Safety Management System (ISMS) is crucial, but additional support provided by the Energy Facility Contractors Group (EFCOG), DOE, and environmental, safety, and health (ES and H) professionals in the field are equally imperative. The panelists discussed the importance of sharing lessons learned as well as are developing performance metrics to track operational and safety successes. This panel focused on current trends in building a strong operational safety culture and will include results from recent national workshops. Safety culture is the foundation of strong operational performance. Panel discussion included best practices from industry, DOE, and US NRC and also review tools being used to measure and evaluate safety culture programs. Panelists with presentations: Strong Safety Culture Promotes Operational Excellence (Kliss McNeel, Patricia Hughes); Safety Culture (Patricia Allen); DOE Safety Culture Improvement (Julie Goeckner); Supporting Safety Culture on the Front Line (Jan Preston); Interdependence of Safety Culture and Organizational Performance (Rizwan Shah)
The present disclosure relates to an optical sensor protection system. The system may have a sensor for receiving an incoming optical signal, a passive sensing and modulation component, and an active sensing and modulation subsystem. The passive sensing and modulation component is configured to sense when a first characteristic is associated with the incoming optical signal is present that adversely affects operation of the sensor, and redirects at least a portion of the incoming optical signal thereof away from the sensor to thus reduce an intensity of the incoming optical signal reaching the sensor. The sensor is located on an image plane downstream of the ISM subsystem, relative to a path of travel of the incoming optical signal. The active sensing and modulation subsystem has an active modulation component and is located upstream of the passive sensing and modulation component, relative to the path of travel of the incoming optical signal, and is also located on a conjugate image plane, and is configured to use the redirected portion of the incoming optical signal as feedback in controlling a modification of the incoming optical signal to reduce a risk of damage to the passive sensing and modulation component.
We study the multi-phase circumgalactic medium (CGM) of emission line galaxies (ELGs) at $z\sim1.5$, traced by MgII$\lambda2796$, $\lambda2803$ and CIV$\lambda1548$, $\lambda1550$ absorption lines, using approximately 7,000 ELG-quasar pairs from the Dark Energy Spectroscopic Instrument. Our results show that both the mean rest equivalent width ($W_{0}$) profiles and covering fractions of MgII and CIV increase with ELG stellar mass at similar impact parameters, but show similar distributions when normalized by the virial radius. Moreover, warm CIV gas has a more extended distribution than cool MgII gas. The dispersion of MgII and CIV gas velocity offsets relative to the galaxy redshifts rises from $\sim100 \, \rm km \, s^{-1}$ within halos to $\sim 200 \, \rm km \, s^{-1}$ beyond. We explore the relationships between MgII and CIV $W_{0}$ and show that the two are not tightly coupled: at a fixed absorption strength of one species, the other varies by several-fold, indicating distinct kinematics between the gas phases traced by each. We measure the line ratios, FeII/MgII and CIV/MgII, of strong MgII absorbers and find that at $<0.2$ virial radius, the FeII/MgII ratio is elevated, while the CIV/MgII ratio is suppressed compared with the measurements on larger scales, both with $\sim4-5\, Ï$ significance. We argue that multiphase gas that is not co-spatial is required to explain the observational results. Finally, by combining with measurements from the literature, we investigate the redshift evolution of CGM properties and estimate the neutral hydrogen, metal, and dust masses in the CGM of DESI ELGs -- found to be comparable to those in the ISM.
We present the stability analysis of two regions, OMC-3 and OMC-4, in the massive and long molecular cloud complex of Orion A. We obtained 214 $\mu$m HAWC + /SOFIA polarization data, and we make use of archival data for the column density and C 18 O (1–0) emission line. We find clear depolarization in both observed regions and that the polarization fraction is anticorrelated with the column density and the polarization-angle dispersion function. We find that the filamentary cloud and dense clumps in OMC-3 are magnetically supercritical and strongly subvirial. This region should be in the gravitational collapse phase and is consistent with many young stellar objects (YSOs) forming in the region. Our histogram of relative orientation (HRO) analysis shows that the magnetic field is dynamically sub-dominant in the dense gas structures of OMC-3. We present the first polarization map of OMC-4. We find that the observed region is generally magnetically subcritical except for an elongated dense core, which could be a result of projection effect of a filamentary structure aligned close to the line of sight. The relative large velocity dispersion and the unusual positive shape parameters at high column densities in the HROs analysis suggest that our viewing angle may be close to axes of filamentary substructures in OMC-4. The dominating strong magnetic field in OMC-4 is unfavourable for star formation and is consistent with much fewer YSOs than in OMC-3.
Context. Both simulations and observations of the interstellar medium show that the study of the relative orientations between filamentary structures and the magnetic field can bring new insight into the role played by magnetic fields in the formation and evolution of filaments and in the process of star formation. Aims. We provide a first application of FilDReaMS, the new method presented in the companion paper to detect and analyze filaments in a given image. The method relies on a template that has the shape of a rectangular bar with variable width. Our goal is to investigate the relative orientations between the detected filaments and the magnetic field. Methods. We apply FilDReaMS to a small sample of four Herschel fields (G210, G300, G82, G202) characterized by different Galactic environments and different evolutionary stages. First, we look for the most prevalent bar widths, and we examine the networks formed by filaments of different bar widths as well as their hierarchical organization. Second, we compare the filament orientations to the magnetic field orientation inferred from Planck polarization data and, for the first time, we study the statistics of the relative orientation angle as functions of both spatial scale and H2 column density. Results. We find preferential relative orientations in the four Herschel fields: small filaments with low column densities tend to be slightly more parallel than perpendicular to the magnetic field; in contrast, large filaments, which all have higher column densities, are oriented nearly perpendicular (or, in the case of G202, more nearly parallel) to the magnetic field. In the two nearby fields (G210 and G300), we observe a transition from mostly parallel to mostly perpendicular relative orientations at an H 2 column density ≃ 1.1 × 10 21 cm -2 and 1.4 × 10 21 cm -2 , respectively, consistent with the results of previous studies. Conclusions. Our results confirm the existence of a coupling between magnetic fields at cloud scales and filaments at smaller scale. They also illustrate the potential of combining Herschel and Planck observations, and they call for further statistical analyses with our dedicated method.
We present the first analysis in NGC 2071-North as a resolved hub–filament featuring a double centre. This ∼1.5 × 1.5 pc 2 scale filament hub contains ∼500 M ⊙ . Seen from Planck, magnetic field lines may have facilitated the gathering of material at this isolated location. The energy balance analysis, supported by infalling gas signatures, reveals that these filaments are currently forming stars. Herschel 100 $\mu$m emission concentrates in the hub, at IRAS 05451+0037 and LkHα 316, and presents diffuse lobes and loops around them. We suggest that such a double centre could be formed, because the converging locations of filament pairs are offset, by 2.3 arcmin (0.27 pc). This distance also matches the diameter of a hub ring, seen in column density and molecular tracers, such as HCO + (1–0) and HCN (1–0), that may indicate a transition and the connection between the hub and the radiating filaments. We argue that all of the three components of the emission star LkHα 316 are in physical association. We find that a ∼0.06-pc-sized gas loop, attached to IRAS 05451+0037, can be seen at wavelengths all the way from the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS)-i to Herschel 100 $\mu$m. These observations suggest that both protostars at the double hub centre are interacting with the cloud material. In our 13 CO data, we do not seem to find the outflow of this region that was identified in the 1980s with much lower resolution.
ABSTRACT The gas metallicity distributions across individual galaxies and across galaxy samples can teach us much about how galaxies evolve. Massive galaxies typically possess negative metallicity gradients, and mass and metallicity are tightly correlated on local scales over a wide range of galaxy masses; however, the precise origins of such trends remain elusive. Here, we employ data from SDSS-IV MaNGA to explore how gas metallicity depends on the local stellar mass density and on galactocentric radius within individual galaxies. We also consider how the strengths of these dependencies vary across the galaxy mass-size plane. We find that radius is more predictive of local metallicity than stellar mass density in extended lower-mass galaxies, while we find density and radius to be almost equally predictive in higher-mass and more compact galaxies. Consistent with previous work, we find a mild connection between metallicity gradients and large-scale environment; however, this is insufficient to explain variations in gas metallicity behaviour across the mass-size plane. We argue our results to be consistent with a scenario in which extended galaxies have experienced smooth gas accretion histories, producing negative metallicity gradients over time. We further argue that more compact and more massive systems have experienced increased merging activity that disrupts this process, leading to flatter metallicity gradients and more dominant density-metallicity correlations within individual galaxies.