bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photometric Calibrations of M-dwarf Metallicity with Markov Chain Monte Carlo and Bayesian Inference
Authors: Duque-Arribas C. , Montes D. , Tabernero H. M. , Caballero J. A. , Gorgas J. , Marfil E. 
Published: February 2023

Abstract
Knowledge of stellar atmospheric parameters (T
eff,

log
g

, [Fe/H]) of M dwarfs can be used to constrain both theoretical stellar models and Galactic chemical evolutionary models, and guide exoplanet searches, but their determination is difficult due to the complexity of the spectra of their cool atmospheres. In our ongoing effort to characterize M dwarfs, and in particular their chemical composition, we carried out multiband photometric calibrations of metallicity for early- and intermediate-type M dwarfs. The third Gaia data release provides high-precision astrometry and three-band photometry. This information, combined with the 2MASS and CatWISE2020 infrared photometric surveys and a sample of 4919 M dwarfs with metallicity values determined with high-resolution spectroscopy by The Cannon and APOGEE spectra, allowed us to study the effect of the metallicity in color–color and color–magnitude diagrams. We divided this sample into two subsamples: we used 1000 stars to train the calibrations with Bayesian statistics and Markov Chain Monte Carlo techniques, and the remaining 3919 stars to check the accuracy of the estimations. We derived several photometric calibrations of metallicity applicable to M dwarfs in the range of −0.45 ≤ [Fe/H] ≤ + 0.45 dex and spectral types down to M5.0 V that yield uncertainties down to the 0.10 dex level. Lastly, we compared our results with other photometric estimations published in the literature for an additional sample of 46 M dwarfs in wide binary systems with FGK-type primary stars and found a great predictive performance.
Investigating Time Variability of X-Ray Absorption in Swift GRBs
Authors: Valan Vlasta , Larsson Josefin , Ahlgren Björn 
Published: February 2023

Abstract
The existence of excess absorption in the X-ray spectra of GRBs is well known, but the primary location of the absorbing material is still uncertain. To gain more knowledge about this, we have performed a time-resolved analysis of the X-ray spectra of 199 GRBs observed by the Swift X-ray telescope, searching for evidence of a decreasing column density (

N

H
,
intr

) that would indicate that the GRBs are ionizing matter in their surroundings. We structured the analysis as Bayesian inference and used an absorbed power law as our baseline model. We also explored alternative spectral models in cases where decreasing absorption was inferred. The analysis reveals seven GRBs that show signs of a decrease in

N

H
,
intr

, but we note that alternative models for the spectral evolution cannot be ruled out. We conclude that the excess absorption in the vast majority of GRBs must originate on large scales of the host galaxies and/or in the intergalactic medium. Our results also imply that an evolving column density is unlikely to affect the spectral analysis of the early X-ray spectra of GRBs. In line with this, we show that estimating the total

N

H
,
intr

from early Swift data in Window Timing mode reveals the same increasing trend with redshift as previous results based on data taken at later times, but with tighter constraints.
Inhomogeneous Enrichment of Radioactive Nuclei in the Galaxy: Deposition of Live 53Mn, 60Fe, 182Hf, and 244Pu into Deep-sea Archives. Surfing the Wave?
Authors: Wehmeyer Benjamin , López Andrés Yagüe , Côté Benoit , K. Pető Maria , Kobayashi Chiaki , Lugaro Maria 
Published: February 2023

Abstract
While modeling the galactic chemical evolution (GCE) of stable elements provides insights to the formation history of the Galaxy and the relative contributions of nucleosynthesis sites, modeling the evolution of short-lived radioisotopes (SLRs) can provide supplementary timing information on recent nucleosynthesis. To study the evolution of SLRs, we need to understand their spatial distribution. Using a three-dimensional GCE model, we investigated the evolution of four SLRs: 53Mn, 60Fe, 182Hf, and 244Pu with the aim of explaining detections of recent (within the last ≈1–20 Myr) deposition of live 53Mn, 60Fe, and 244Pu of extrasolar origin into deep-sea reservoirs. We find that core-collapse supernovae are the dominant propagation mechanism of SLRs in the Galaxy. This results in the simultaneous arrival of these four SLRs on Earth, although they could have been produced in different astrophysical sites, which can explain why live extrasolar 53Mn, 60Fe, and 244Pu are found within the same, or similar, layers of deep-sea sediments. We predict that 182Hf should also be found in such sediments at similar depths.
PHANGS–JWST First Results: Duration of the Early Phase of Massive Star Formation in NGC 628
Authors: Kim Jaeyeon , Chevance Mélanie , Kruijssen J. M. Diederik , Barnes Ashley. T. , Bigiel Frank , Blanc Guillermo A. , Boquien Médéric , Cao Yixian , Congiu Enrico , Dale Daniel A. , Egorov Oleg V. , Faesi Christopher M. , Glover Simon C. O. , Grasha Kathryn , Groves Brent , Hassani Hamid , Hughes Annie , Klessen Ralf S. , Kreckel Kathryn , Larson Kirsten L. , Lee Janice C. , Leroy Adam K. , Liu Daizhong , Longmore Steven N. , Meidt Sharon E. , Pan Hsi-An , Pety Jérôme , Querejeta Miguel , Rosolowsky Erik , Saito Toshiki , Sandstrom Karin , Schinnerer Eva , Smith Rowan J. , Usero Antonio , Watkins Elizabeth J. , Williams Thomas G. 
Published: February 2023

Abstract
The earliest stages of star formation, when young stars are still deeply embedded in their natal clouds, represent a critical phase in the matter cycle between gas clouds and young stellar regions. Until now, the high-resolution infrared observations required for characterizing this heavily obscured phase (during which massive stars have formed, but optical emission is not detected) could only be obtained for a handful of the most nearby galaxies. One of the main hurdles has been the limited angular resolution of the Spitzer Space Telescope. With the revolutionary capabilities of the James Webb Space Telescope (JWST), it is now possible to investigate the matter cycle during the earliest phases of star formation as a function of the galactic environment. In this Letter, we demonstrate this by measuring the duration of the embedded phase of star formation and the implied time over which molecular clouds remain inert in the galaxy NGC 628 at a distance of 9.8 Mpc, demonstrating that the cosmic volume where this measurement can be made has increased by a factor of >100 compared to Spitzer. We show that young massive stars remain embedded for

5.1

−
1.4

+
2.7

Myr (

2.3

−
1.4

+
2.7

Myr of which being heavily obscured), representing ∼20% of the total cloud lifetime. These values are in broad agreement with previous measurements in five nearby (D < 3.5 Mpc) galaxies and constitute a proof of concept for the systematic characterization of the early phase of star formation across the nearby galaxy population with the PHANGS–JWST survey.
PHANGS–JWST First Results: Stellar-feedback-driven Excitation and Dissociation of Molecular Gas in the Starburst Ring of NGC 1365?
Authors: Liu Daizhong , Schinnerer Eva , Cao Yixian , Leroy Adam , Usero Antonio , Rosolowsky Erik , Kruijssen J. M. Diederik , Chevance Mélanie , Glover Simon C. O. , Sormani Mattia C. , Bolatto Alberto D. , Sun Jiayi , Stuber Sophia K. , Teng Yu-Hsuan , Bigiel Frank , Bešlić Ivana , Grasha Kathryn , Henshaw Jonathan D. , Barnes Ashley T. , den Brok Jakob S. , Saito Toshiki , Dale Daniel A. , Watkins Elizabeth J. , Pan Hsi-An , Klessen Ralf S. , Emsellem Eric , Anand Gagandeep S. , Deger Sinan , Egorov Oleg V. , Faesi Christopher M. , Hassani Hamid , Larson Kirsten L. , Lee Janice C. , Lopez Laura A. , Pety Jérôme , Sandstrom Karin , Thilker David A. , Whitmore Bradley C. , Williams Thomas G. 
Published: February 2023

Abstract
We compare embedded young massive star clusters (YMCs) to (sub-)millimeter line observations tracing the excitation and dissociation of molecular gas in the starburst ring of NGC 1365. This galaxy hosts one of the strongest nuclear starbursts and richest populations of YMCs within 20 Mpc. Here we combine near-/mid-IR PHANGS–JWST imaging with new Atacama Large Millimeter/submillimeter Array multi-J CO (1–0, 2–1 and 4–3) and [C
i] (1–0) mapping, which we use to trace CO excitation via R
42 = I
CO(4−3)/I
CO(2−1) and R
21 = I
CO(2−1)/I
CO(1−0) and dissociation via R
CICO = I
[CI](1−0)/I
CO(2−1) at 330 pc resolution. We find that the gas flowing into the starburst ring from northeast to southwest appears strongly affected by stellar feedback, showing decreased excitation (lower R
42) and increased signatures of dissociation (higher R
CICO) in the downstream regions. There, radiative-transfer modeling suggests that the molecular gas density decreases and temperature and [CI/CO] abundance ratio increase. We compare R
42 and R
CICO with local conditions across the regions and find that both correlate with near-IR 2 μm emission tracing the YMCs and with both polycyclic aromatic hydrocarbon (11.3 μm) and dust continuum (21 μm) emission. In general, R
CICO exhibits ∼0.1 dex tighter correlations than R
42, suggesting C
i to be a more sensitive tracer of changing physical conditions in the NGC 1365 starburst than CO (4–3). Our results are consistent with a scenario where gas flows into the two arm regions along the bar, becomes condensed/shocked, forms YMCs, and then these YMCs heat and dissociate the gas.
PHANGS–JWST First Results: Rapid Evolution of Star Formation in the Central Molecular Gas Ring of NGC 1365
Authors: Schinnerer Eva , Emsellem Eric , Henshaw Jonathan D. , Liu Daizhong , Meidt Sharon E. , Querejeta Miguel , Renaud Florent , Sormani Mattia C. , Sun Jiayi , Egorov Oleg V. , Larson Kirsten L. , Leroy Adam K. , Rosolowsky Erik , Sandstrom Karin M. , Williams T. G. , Barnes Ashley. T. , Bigiel F. , Chevance Mélanie , Cao Yixian , Chandar Rupali , Dale Daniel A. , Eibensteiner Cosima , Glover Simon C. O. , Grasha Kathryn , Hannon Stephen , Hassani Hamid , Kim Jaeyeon , Klessen Ralf S. , Kruijssen J. M. Diederik , Murphy Eric J. , Neumann Justus , Pan Hsi-An , Pety Jérôme , Saito Toshiki , Stuber Sophia K. , Treß Robin G. , Usero Antonio , Watkins Elizabeth J. , Whitmore Bradley C. ,   PHANGS
Published: February 2023

Abstract
Large-scale bars can fuel galaxy centers with molecular gas, often leading to the development of dense ringlike structures where intense star formation occurs, forming a very different environment compared to galactic disks. We pair ∼0.″3 (30 pc) resolution new JWST/MIRI imaging with archival ALMA CO(2–1) mapping of the central ∼5 kpc of the nearby barred spiral galaxy NGC 1365 to investigate the physical mechanisms responsible for this extreme star formation. The molecular gas morphology is resolved into two well-known bright bar lanes that surround a smooth dynamically cold gas disk (R
gal ∼ 475 pc) reminiscent of non-star-forming disks in early-type galaxies and likely fed by gas inflow triggered by stellar feedback in the lanes. The lanes host a large number of JWST-identified massive young star clusters. We find some evidence for temporal star formation evolution along the ring. The complex kinematics in the gas lanes reveal strong streaming motions and may be consistent with convergence of gas streamlines expected there. Indeed, the extreme line widths are found to be the result of inter-“cloud” motion between gas peaks; ScousePy decomposition reveals multiple components with line widths of 〈σ
CO,scouse〉 ≈ 19 km s−1 and surface densities of

〈

Σ

H

2

,
scouse

〉

≈

800

M

⊙

pc

−
2

, similar to the properties observed throughout the rest of the central molecular gas structure. Tailored hydrodynamical simulations exhibit many of the observed properties and imply that the observed structures are transient and highly time-variable. From our study of NGC 1365, we conclude that it is predominantly the high gas inflow triggered by the bar that is setting the star formation in its CMZ.
PHANGS–JWST First Results: Variations in PAH Fraction as a Function of ISM Phase and Metallicity
Authors: Chastenet Jérémy , Sutter Jessica , Sandstrom Karin , Belfiore Francesco , Egorov Oleg V. , Larson Kirsten L. , Leroy Adam K. , Liu Daizhong , Rosolowsky Erik , Thilker David A. , Watkins Elizabeth J. , Williams Thomas G. , Barnes Ashley. T. , Bigiel Frank , Boquien Médéric , Chevance Mélanie , Chiang 江 I-Da 宜 達 , Dale Daniel A. , Kruijssen J. M. Diederik , Emsellem Eric , Grasha Kathryn , Groves Brent , Hassani Hamid , Hughes Annie , Kreckel Kathryn , Meidt Sharon E. , Rickards Vaught Ryan J. , Sardone Amy , Schinnerer Eva 
Published: February 2023

Abstract
We present maps tracing the fraction of dust in the form of polycyclic aromatic hydrocarbons (PAHs) in IC 5332, NGC 628, NGC 1365, and NGC 7496 from JWST/MIRI observations. We trace the PAH fraction by combining the F770W (7.7 μm) and F1130W (11.3 μm) filters to track ionized and neutral PAH emission, respectively, and comparing the PAH emission to F2100W, which traces small, hot dust grains. We find the average R
PAH = (F770W + F1130W)/F2100W values of 3.3, 4.7, 5.1, and 3.6 in IC 5332, NGC 628, NGC 1365, and NGC 7496, respectively. We find that H ii regions traced by MUSE Hα show a systematically low PAH fraction. The PAH fraction remains relatively constant across other galactic environments, with slight variations. We use CO+Hi +Hα to trace the interstellar gas phase and find that the PAH fraction decreases above a value of

I

H
α

/

Σ

H
I
+

H

2

∼

10

37.5

erg

s

−
1

kpc

−
2

(

M

⊙

pc

−
2

)

−
1

in all four galaxies. Radial profiles also show a decreasing PAH fraction with increasing radius, correlated with lower metallicity, in line with previous results showing a strong metallicity dependence to the PAH fraction. Our results suggest that the process of PAH destruction in ionized gas operates similarly across the four targets.
PHANGS–JWST First Results: Massive Young Star Clusters and New Insights from JWST Observations of NGC 1365
Authors: Whitmore Bradley C. , Chandar Rupali , Rodríguez M. Jimena , Lee Janice C. , Emsellem Eric , Floyd Matthew , Kim Hwihyun , Kruijssen J. M. Diederik , Mok Angus , Sormani Mattia C. , Boquien Médéric , Dale Daniel A. , Faesi Christopher M. , Henny Kiana F. , Hannon Stephen , Thilker David A. , White Richard L. , Barnes Ashley T. , Bigiel F. , Chevance Mélanie , Henshaw Jonathan D. , Klessen Ralf S. , Leroy Adam K. , Liu Daizhong , Maschmann Daniel , Meidt Sharon E. , Rosolowsky Erik , Schinnerer Eva , Sun Jiayi , Watkins Elizabeth J. , Williams Thomas G. 
Published: February 2023

Abstract
A primary new capability of JWST is the ability to penetrate the dust in star-forming galaxies to identify and study the properties of young star clusters that remain embedded in dust and gas. In this Letter we combine new infrared images taken with JWST with our optical Hubble Space Telescope (HST) images of the starbursting barred (Seyfert2) spiral galaxy NGC 1365. We find that this galaxy has the richest population of massive young clusters of any known galaxy within 30 Mpc, with ∼30 star clusters that are more massive than 106
M
⊙ and younger than 10 Myr. Sixteen of these clusters are newly discovered from our JWST observations. An examination of the optical images reveals that 4 of 30 (∼13%) are so deeply embedded that they cannot be seen in the Hubble I band (A

V
≳ 10 mag), and that 11 of 30 (∼37%) are missing in the HST B band, so age and mass estimates from optical measurements alone are challenging. These numbers suggest that massive clusters in NGC 1365 remain completely obscured in the visible for ∼1.3 ± 0.7 Myr and are either completely or partially obscured for ∼3.7 ± 1.1 Myr. We also use the JWST observations to gain new insights into the triggering of star cluster formation by the collision of gas and dust streamers with gas and dust in the bar. The JWST images reveal previously unknown structures (e.g., bridges and overshoot regions from stars that form in the bar) that help us better understand the orbital dynamics of barred galaxies and associated star-forming rings. Finally, we note that the excellent spatial resolution of the NIRCAM F200W filter provides a better way to separate barely resolved compact clusters from individual stars based on their sizes.
PHANGS–JWST First Results: The Dust Filament Network of NGC 628 and Its Relation to Star Formation Activity
Authors: Thilker David A. , Lee Janice C. , Deger Sinan , Barnes Ashley T. , Bigiel Frank , Boquien Médéric , Cao Yixian , Chevance Mélanie , Dale Daniel A. , Egorov Oleg V. , Glover Simon C. O. , Grasha Kathryn , Henshaw Jonathan D. , Klessen Ralf S. , Koch Eric , Kruijssen J. M. Diederik , Leroy Adam K. , Lessing Ryan A. , Meidt Sharon E. , Pinna Francesca , Querejeta Miguel , Rosolowsky Erik , Sandstrom Karin M. , Schinnerer Eva , Smith Rowan J. , Watkins Elizabeth J. , Williams Thomas G. , Anand Gagandeep S. , Belfiore Francesco , Blanc Guillermo A. , Chandar Rupali , Congiu Enrico , Emsellem Eric , Groves Brent , Kreckel Kathryn , Larson Kirsten L. , Liu Daizhong , Pessa Ismael , Whitmore Bradley C. 
Published: February 2023

Abstract
PHANGS–JWST mid-infrared (MIR) imaging of nearby spiral galaxies has revealed ubiquitous filaments of dust emission in intricate detail. We present a pilot study to systematically map the dust filament network (DFN) at multiple scales between 25 and 400 pc in NGC 628. MIRI images at 7.7, 10, 11.3, and 21 μm of NGC 628 are used to generate maps of the filaments in emission, while PHANGS–HST B-band imaging yields maps of dust attenuation features. We quantify the correspondence between filaments traced by MIR thermal continuum/polycyclic aromatic hydrocarbon (PAH) emission and filaments detected via extinction/scattering of visible light; the fraction of MIR flux contained in the DFN; and the fraction of H ii regions, young star clusters, and associations within the DFN. We examine the dependence of these quantities on the physical scale at which the DFN is extracted. With our highest-resolution DFN maps (25 pc filament width), we find that filaments in emission and attenuation are cospatial in 40% of sight lines, often exhibiting detailed morphological agreement; that ∼30% of the MIR flux is associated with the DFN; and that 75%–80% of the star formation in H ii regions and 60% of the mass in star clusters younger than 5 Myr are contained within the DFN. However, the DFN at this scale is anticorrelated with looser associations of stars younger than 5 Myr identified using PHANGS–HST near-UV imaging. We discuss the impact of these findings on studies of star formation and the interstellar medium, and the broad range of new investigations enabled by multiscale maps of the DFN.
Revised Radiative Response Coefficients for the Curiosity Rover Mastcam from Direct Solar Images and Analog Tests
Authors: Lemmon M. T. , Bell J. F. , Hayes A. G. 
Published: February 2023

Abstract
We have used solar images taken by the Curiosity rover’s Mastcam to derive new radiometric response coefficients. In addition, we used calibration data from the Perseverance rover’s Mastcam-Z instrument, which used the same detector, to estimate temperature sensitivity of the radiative response. The new coefficients allow calibration of raw data to radiance using the illuminant (the Sun) as the calibration source. Compared to the original pre-flight and early in-flight calibration, the revised calibration is expected to be more consistent across instrument temperature and allow for a self-consistent conversion to radiance factor values when contemporaneous calibration target images are not available or not appropriate. The revised coefficients were incorporated in a recalibration of Mastcam radiance products.
Polyploidy and its relevance in crop improvement
Authors: Omere E.A. , Nwaoguala C.N.C. , Emede T.O. 
Published: February 2023

Many areas of research in crop production have been geared towards crop improvement and increased yield. Crop improvement include but not restricted to; plant introduction and acclimatization, domestication, ploidy manipulation (polyploidization), recombinant DNA technology, crossing for superior selection (cultivar development), molecular genetics, etc. Polyploidy is a condition where the genome of an organism has more than the usual number of complete sets of chromosomes and the product of this phenomenon is called a Polyploid. Polyploidy occurs naturally, and can be induced chemically using antimitotic agents or physically using protoplast fusion and temperature shock. It is mostly artificially induced through a process called polyploidization. Polyploids are more advantageous in important plant attributes than the regular diploid. Relative success has been reported in the application of polyploidization for crop improvement which resulted chiefly in increased amount of beneficial secondary metabolites (phytochemicals), larger stomata and leaves,improved adaptation to stress and unfavourable conditions, to mention but a few. Therefore, it is imperative to state that polyploidy is an area of research that has been and will continually be deployed in crop improvement .
Effects of processing on bacteriological, proximate, hydrocarbon content and organoleptic indices of Scomber scombrus
Authors: James I.I. , Etuk C.U. , Ben M.G. , Okon R.S. , Essien A.M. , Asuquo A. , Umoren E.A. 
Published: February 2023

Effects of boiling, smoking and frying on the organoleptic quality, bacteriological count, proximate composition and total hydrocarbon contents of Scomber scombrus fish sold in Ikot Ekpene Metropolis were investigated. Fillets of fresh S. scombrus were made, and processed by smoking, boiling and frying methods. Portions of the fish sample were aliquoted, and used to carry out sensory evaluation, plating aliquots of diluents onto nutrient agar plates (for total viable count (TVC), and on Manitol Salt agar (for total staphylococcal count (TSC). Standard methods were used to determine moisture, ash, total lipids and crude protein contents. Total hydrocarbon content was determined by toluene extraction and measurement of absorbance of filtrate spectrophotometrically. Sensory quality obtained using smoke-drying and frying methods scored significantly higher than that of boiling and the control (p<0.05). TVC of samples were lower than in the control fish sample after processing, increasing over the 4-day period, although negligible when compared to the control. TVC were lowest in samples processed by frying. TSC decreased in all fish samples after processing, except in the control fish sample. Fried Scomber scombrus samples also showed no trace of S. aureus. Moisture, lipid, crude protein and ash contents of control S. scombrus were 68.78±1.02, 2.03±0.11, 20.14±0.06 and 0.09±0.32 respectively. The changes in moisture, lipid, crude protein and ash contents were statistically significant (P<0.05) in processed fish samples. Total hydrocarbon content also increased in processed fish; 2.914±0.005 for smoke-dried, 2.168±0.001 for fried and 1.538±0.009 for boiled, as against 1.412±0.011 in the control sample. Overall bacteriological quality indices, the proximate content and total hydrocarbon contents of samples demonstrated frying and smoking as preferable processing methods for Scomber scombrus.