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NASA NTRS2002

Forecasting Coronal Mass Ejections from Vector Magnetograms

In a 17 vector magnetogram study of 12 bipolar active regions (Falconer, Moore, & Gary, 2002, ApJ in press), we correlated four quantitative global magnetic measures with the Coronal Mass Ejections (CME) productivity of the active region. The global measures included a measure of active region size, the total magnetic flux phi and three measures of an active region global nonpotentiality 1) the net current (I (sub N)), 2) the length of the strong-shear, strong-field main neutral line (L(sub SS)) and 3) and the normalized twist (alpha = muIN/PHI). The CME productivity was determined from YOHKOH/SXT observations, Geostationary Operational Environmental Satellite (GOES), and when possible Solar and Heliospheric Observatory/Large Angle and Spectrometric Coronagraph Experiment (SOHO/LASCO) observations within 12 days of the day of the magnetogram. We found that the three measures of global nonpotentiality (I(sub N), L(sub SS), alpha) were all well correlated (greater than 99% confidence level) with an active region's CME productivity. The sample size was to small to confirm if there was a statistical significant correlation of the globally nonscientist measures with future CME activity (i.e. from the date of the magnetogram forward). We are doubling our sample, and will report on the statistical significance of global nonpotentiality as a predictor of future CME productivity. The new active regions are all from the first year of the upgraded MSFC vector magnetograms. This work, is funded by NSF through the Space Weather Program, by NASA through the Living with the Star, Targeted Research and Technology, and by NASA Solar Physics Supporting Research and Technology Program. The upgrade to the MSFC vector magnetograph was supported by the High Energy Solar Spectroscopic Imager (HESSI) mission.

Falconer, D. A.↗
DOE OSTI2024

Camelina circRNA landscape: Implications for gene regulation and fatty acid metabolism

Abstract Circular RNAs (circRNAs) are closed‐loop RNAs forming a covalent bond between their 3′ and 5′ ends, the back splice junction (BSJ), rendering them resistant to exonucleases and thus more stable compared to linear RNAs. Identification of circRNAs and distinction from their cognate linear RNA is only possible by sequencing the BSJ that is unique to the circRNA. CircRNAs are involved in the regulation of their cognate RNAs by increasing transcription rates, RNA stability, and alternative splicing. We have identified circRNAs from C. sativa that are associated with the regulation of germination, light response, and lipid metabolism. We sequenced light‐grown and etiolated seedlings after 5 or 7 days post‐germination and identified a total of 3447 circRNAs from 2763 genes. Most circRNAs originate from a single homeolog of the three subgenomes from allohexaploid camelina and correlate with higher ratios of alternative splicing of their cognate genes. A network analysis shows the interactions of select miRNA:circRNA:mRNAs for regulation of transcript stabilities where circRNA can act as a competing endogenous RNA. Several key lipid metabolism genes can generate circRNA, and we confirmed the presence of KASII circRNA as a true circRNA. CircRNA in camelina can be a novel target for breeding and engineering efforts.

Utley, Delecia [Department of Plant and Microbial ↗
DOE OSTI2016

Comparison of C-arm Computed Tomography and Digital Subtraction Angiography in Patients with Chronic Thromboembolic Pulmonary Hypertension

PurposeTo assess the feasibility and diagnostic performance of contrast-enhanced, C-arm computed tomography (CACT) of the pulmonary arteries compared to digital subtraction angiography (DSA) in patients suffering from chronic thromboembolic pulmonary hypertension (CTEPH).MaterialsFifty-two patients with CTEPH underwent ECG-gated DSA and contrast-enhanced CACT. Two readers (R1, R2) independently evaluated pulmonary artery segments and their sub-segmental branching using DSA and CACT for optimal image quality. Afterwards, the diagnostic findings, i.e., intraluminal filling defects, stenosis, and occlusion, were compared. Inter-modality and inter-observer agreement was calculated, and subsequently consensus reading was done and correlated to a reference standard representing the overall consensus of both modalities. Fisher’s exact test and Cohen’s Kappa were applied.ResultsA total of 1352 pulmonary segments were evaluated, of which 1255 (92.8 %) on DSA and 1256 (92.9 %) on CACT were rated to be fully diagnostic. The main causes of the non-diagnostic image quality were motion artifacts on CACT (R1:37, R2:78) and insufficient contrast enhancement on DSA (R1:59, R2:38). Inter-observer agreement was good for DSA (κ = 0.74) and CACT (κ = 0.75), while inter-modality agreement was moderate (R1: κ = 0.46, R2: κ = 0.47). Compared to the reference standard, the inter-modality agreement for CACT was excellent (κ = 0.96), whereas it was inferior for DSA (κ = 0.61) due to the higher number of abnormal consensus findings read as normal on DSA.ConclusionCACT of the pulmonary arteries is feasible and provides additional information to DSA. CACT has the potential to improve the diagnostic work-up of patients with CTEPH and may be particularly useful prior to surgical or interventional treatment.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2018

Nanoscale Solute Partitioning and Carbide Precipitation in a Multiphase TRIP Steel Analyzed by Atom Probe Tomography

Nanoscale solute partitioning across multiple constituent phases in a 980-grade quenched and partitioned (Q&P) steel was analyzed using atom probe tomography (APT). The Q&P process was used to increase the C content in the retained austenite phase thereby improving its stability under plastic straining. Significant carbon enrichment of austenite was measured with decreased levels of C in martensite and almost depleted C content in ferrite, supporting the C partitioning mechanism in the literature. The APT analysis of retained austenite surrounded by martensite demonstrated a higher amount of C content compared with retained austenite surrounded by the ferrite phase. Lath and discrete carbide particle precipitation was also observed inside martensite colonies, tying up C and reducing the total amount of C available for austenite stabilization. In addition, the partitioning of Mn and other minor elements was quantitatively investigated by correlating APT and SEM-EBSD. Furthermore, these techniques provide a robust methodology for analyzing nanoscale compositional partitioning in multiphase steels, TRIP steels in particular, which can be used to better explain their microstructure-mechanical property relationships.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Anisotropic structure in a vapor-deposited Pd-based metallic glass

The understanding of the structure of amorphous solids beyond nearest-neighbors has long been sought after. While recent works have demonstrated evidence for medium-range ordering and its importance for the physical properties of glassy systems, few have investigated mesoscopic structural correlations beyond a few nanometers. In this work, combining X-ray nano-diffraction with high-energy X-ray total scattering with a small focus, we have not only found structural anisotropy in a vapor-deposited Pd 77.5 Cu 6 Si 16.5 metallic glass sample which appears to show two distinct and well-defined structures in different directions, but also obtained detailed characterizations of this anisotropic structure in real space. Upon annealing, the sample loses the long-range anisotropy, and at the same time, it appears to densify with a contraction of higher-order coordination shells. In light of recent works, our results may indicate a transition between two structures in the sample with different densities, medium-range ordering, and degrees of anisotropy. We expect these results to be relevant to a larger family of metallic glass systems, where similar discoveries may be made with the use of high-quality, small-focus X-ray beams.

36 MATERIALS SCIENCE↗
DOE OSTI2013

A Comparison of Amplitude-Based and Phase-Based Positron Emission Tomography Gating Algorithms for Segmentation of Internal Target Volumes of Tumors Subject to Respiratory Motion

Purpose: To quantitatively compare the accuracy of tumor volume segmentation in amplitude-based and phase-based respiratory gating algorithms in respiratory-correlated positron emission tomography (PET). Methods and Materials: List-mode fluorodeoxyglucose-PET data was acquired for 10 patients with a total of 12 fluorodeoxyglucose-avid tumors and 9 lymph nodes. Additionally, a phantom experiment was performed in which 4 plastic butyrate spheres with inner diameters ranging from 1 to 4 cm were imaged as they underwent 1-dimensional motion based on 2 measured patient breathing trajectories. PET list-mode data were gated into 8 bins using 2 amplitude-based (equal amplitude bins [A1] and equal counts per bin [A2]) and 2 temporal phase-based gating algorithms. Gated images were segmented using a commercially available gradient-based technique and a fixed 40% threshold of maximum uptake. Internal target volumes (ITVs) were generated by taking the union of all 8 contours per gated image. Segmented phantom ITVs were compared with their respective ground-truth ITVs, defined as the volume subtended by the tumor model positions covering 99% of breathing amplitude. Superior-inferior distances between sphere centroids in the end-inhale and end-exhale phases were also calculated. Results: Tumor ITVs from amplitude-based methods were significantly larger than those from temporal-based techniques (P=.002). For lymph nodes, A2 resulted in ITVs that were significantly larger than either of the temporal-based techniques (P<.0323). A1 produced the largest and most accurate ITVs for spheres with diameters of ≥2 cm (P=.002). No significant difference was shown between algorithms in the 1-cm sphere data set. For phantom spheres, amplitude-based methods recovered an average of 9.5% more motion displacement than temporal-based methods under regular breathing conditions and an average of 45.7% more in the presence of baseline drift (P<.001). Conclusions: Target volumes in images generated from amplitude-based gating are larger and more accurate, at levels that are potentially clinically significant, compared with those from temporal phase-based gating.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2014

Synthesis and characterization of antiperovskite nitrides GaNCr{sub 3−x}Mn{sub x}

The effects of Mn-doping on the crystal structure, magnetic and electrical/thermal transport properties of GaNCr{sub 3−x}Mn{sub x} (0≤x≤1.5) have been investigated systematically. As a result, the lattice constant and the residual resistivity increase, while the residual resistivity ratio, electron thermal conductivity, and room-temperature carrier concentration decrease with increasing Mn-doping level. The ground state of parent compound GaNCr{sub 3} is nonmagnetic, interestingly, the ferrimagnetism and antiferromagnetism are observed in Mn-doped samples GaNCr{sub 3−x}Mn{sub x}. Correspondingly, around the antiferromagnetic transition of GaNCr{sub 3−x}Mn{sub x} the correlation effect is studied. Furthermore, the analysis of thermal conductivity data suggests that the electron thermal conductivity plays a major role in total thermal conductivity of GaNCr{sub 3} at low temperatures, while the phonon thermal conductivity is dominant for Mn-doped GaNCr{sub 3} in the whole temperature of 5–330 K. The positive values of Seebeck coefficient and Hall coefficient indicate that the nature of charge carrier is hole-type in GaNCr{sub 3−x}Mn{sub x}. - Graphical abstract: The Rietveld refinement and structural properties of GaNCr{sub 3−x}Mn{sub x}. Display Omitted - Highlights: • Polycrystalline GaNCr{sub 3−x}Mn{sub x} are synthesized by using the solid state reaction method. • A good quality of samples is verified by Rietveld refinement and RRR values. • Antiferromagnetic and ferromagnetic competitions are induced by Mn-doping. • We present a comprehensive understanding of physical properties of GaNCr{sub 3−x}Mn{sub x}.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2018

A novel IMRT planning study by using the fixed-jaw method in the treatment of peripheral lung cancer with mediastinal lymph node metastasis

Intensity-modulated radiotherapy (IMRT) is an important technology in cancer radiotherapy. In the current planning system, such as in the Pinnacle{sup 3} system, jaw positions are automatically set to cover all target volumes, and many medical centers in developing countries are not equipped with linear accelerators with a jaw tracing function. As solitary lesions are often located in patients, the resulting radiation leakage and transmission increase the dose exposure in surrounding critical organs, although blocked by multileaf collimator (MLC) leaves. We therefore designed a method to manually fix jaw positions, which further reduces doses. We particularly focused on the patients of peripheral lung cancer combined with mediastinal lymph node metastasis, as our medical center mainly targets lung cancer. We designed 2 treatment plans for each patient with the same optimization parameters, i.e., the plan of automatically chosen jaw positions (jaw auto-chosen plan) and the plan of fixed-jaw positions (fixed-jaw plan). In the latter plan, jaws were manually fixed for tumors in lung and in mediastinal lymph node metastases, respectively. We found that both plans met the clinical requirements, and the D{sub 2}, D{sub 98}, conformation number (CN), and homogeneity index (HI) for planning target volume (PTV) had no significant differences between the 2 plans. Importantly, the machine units (MUs) for fixed-jaw plans were 50%~60% more than routine jaw auto-chosen plans, whereas the V{sub 5}, V{sub 10}, V{sub 20}, V{sub 30}, and the mean dose in the total lung and the ipsilateral lung were less than the routine jaw auto-chosen plans. Dose-volume values D{sub 1} for the spinal cord and D{sub 2}, V{sub 40}, V{sub 60} for the heart existed no significant differences for 2 plans. In the fixed-jaw method, the total lung TLV{sub 5}-â–³V{sub ab} and TLV{sub 10}-â–³V{sub ab} values had a moderate positive correlation with the lung radiation leakage and the transmission area reduction. We concluded that the fixed-jaw plan is superior to the routine jaw auto-chosen plan in reducing the radiation exposure of surrounding critical organs, which will benefit the IMRT application.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2015

Changes in cholesterol homeostasis and acute phase response link pulmonary exposure to multi-walled carbon nanotubes to risk of cardiovascular disease

Adverse lung effects following pulmonary exposure to multi-walled carbon nanotubes (MWCNTs) are well documented in rodents. However, systemic effects are less understood. Epidemiological studies have shown increased cardiovascular disease risk after pulmonary exposure to airborne particles, which has led to concerns that inhalation exposure to MWCNTs might pose similar risks. We analyzed parameters related to cardiovascular disease, including plasma acute phase response (APR) proteins and plasma lipids, in female C57BL/6 mice exposed to a single intratracheal instillation of 0, 18, 54 or 162 μg/mouse of small, entangled (CNT{sub Small}, 0.8 ± 0.1 μm long) or large, thick MWCNTs (CNT{sub Large}, 4 ± 0.4 μm long). Liver tissues and plasma were harvested 1, 3 and 28 days post-exposure. In addition, global hepatic gene expression, hepatic cholesterol content and liver histology were used to assess hepatic effects. The two MWCNTs induced similar systemic responses despite their different physicochemical properties. APR proteins SAA3 and haptoglobin, plasma total cholesterol and low-density/very low-density lipoprotein were significantly increased following exposure to either MWCNTs. Plasma SAA3 levels correlated strongly with pulmonary Saa3 levels. Analysis of global gene expression revealed perturbation of the same biological processes and pathways in liver, including the HMG-CoA reductase pathway. Both MWCNTs induced similar histological hepatic changes, with a tendency towards greater response following CNT{sub Large} exposure. Overall, we show that pulmonary exposure to two different MWCNTs induces similar systemic and hepatic responses, including changes in plasma APR, lipid composition, hepatic gene expression and liver morphology. The results link pulmonary exposure to MWCNTs with risk of cardiovascular disease. - Highlights: • Systemic and hepatic alterations were evaluated in female mice following MWCNT instillation. • Despite being physicochemically different, the two MWCNTs induced a similar systemic acute phase response. • We found a close correlation between plasma SAA levels and pulmonary Saa3 transcription levels. • Similar changes in plasma lipid levels and in the hepatic transcriptome were observed. • Our results indicate a link between pulmonary exposure to MWCNTs with risk of cardiovascular disease.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Relationship of antioxidant and oxidative stress markers in different organs following copper toxicity in a rat model

Copper (Cu) at a higher level becomes toxic and it can catalyze the formation of highly reactive hydroxyl radical. We report the vulnerability of liver, kidney and brain to different dose of copper sulfate (CuSO{sub 4}) induced oxidative stress at different time duration. Fifty-four male Wistar rats (weight range = 205 ± 10 g) were equally divided into three groups. CuSO{sub 4} was administered orally to the experimental groups (Group-II and III) up to 90 days in a dose of 100 and 200 mg/Kg body weight per day. Saline water was given to the control group (Group-I). At the end of 30, 60 and 90 days of administration, neurobehavioral studies were done and six rats from each group were sacrificed. Their liver, kidney and brain tissues were subjected for Cu, glutathione (GSH), malondialdehyde (MDA) and total antioxidant capacity (TAC) assay. Blood urea nitrogen (BUN), serum creatinine, bilirubin and transaminases were measured. GSH, TAC and MDA levels were correlated with the markers of respective organ dysfunction. Administration of CuSO{sub 4} resulted in increased free Cu and MDA level, and decrease GSH and TAC levels in group-II and III compared with group-I. In experimental groups, the reduction in TAC and GSH levels was maximum in liver tissue followed by brain and kidney; whereas increase in MDA level was highest in liver followed by brain and kidney at 30, 60 and 90 days. TAC and GSH levels in the liver inversely correlated with serum transaminases and bilirubin, and tissue free Cu, and positively correlated with MDA levels. Free Cu level in kidney tissue and BUN inversely correlated with TAC and GSH, and positively with MDA level. Grip-strength, rotarod and Y-maze findings were inversely correlated with brain free Cu and MDA levels and positively with GSH and TAC levels. The oxidative stress was highest in liver followed by brain and kidney after oral CuSO{sub 4} exposure in a rat model. These levels correlated with the respective organ dysfunction and tissue free Cu concentration. - Highlights: • Oral dosing of CuSO{sub 4} leads to oxidative stress in liver, brain and kidney. • Liver has maximum oxidative stress followed by brain and kidney. • Oxidative stress correlated with the respective organ dysfunction and tissue Cu concentration.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Spatial-temporal variations of dissolved organic nitrogen molecular composition in agricultural runoff water

Leaching of dissolved organic nitrogen (DON) has been reported as a pathway of N loss from agriculture, but the molecular composition of DON in agricultural water is poorly understood. Runoff water samples were collected from citrus grove furrows (CGF), ditches (CGD) and pasture ditches (PD) in four seasons. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) was used to investigate molecular composition of DON. Chemodiversity index of DON had spatiotemporal variations, while the molecular composition of total DON showed minimal variations, except for PD in November. Lignin derivatives constituted 61% of the total DON compounds. Relative abundance of aliphatic compounds, char and condensed aromatics of unique DON compounds varied spatiotemporally and had a significant correlation with DON concentration. Aromaticity index decreased from CGF to connected CGD, implying that photodegradation is possibly the dominant process that alters molecular composition of aquatic DON during the transport. Significant differences in unique DON composition between CGD and PD indicates that fertilization and land use affect DON composition. The information on molecular characterization of DON should be useful for tracking DON source and developing technologies to remove DON in the agricultural runoff water.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2015

Oxygen-dependent acetylation and dimerization of the corepressor CtBP2 in neural stem cells

The transcriptional corepressor CtBP2 is essential for proper development of the nervous system. The factor exerts its repression by interacting in complexes with chromatin-modifying factors such as histone deacetylases (HDAC) 1/2 and the histone demethylase LSD1/KDM1. Notably, the histone acetyl transferase p300 acetylates CtBP2 and this is an important regulatory event of the activity and subcellular localization of the protein. We recently demonstrated an essential role for CtBPs as sensors of microenvironmental oxygen levels influencing the differentiation potential of neural stem cells (NSCs), but it is not known whether oxygen levels influence the acetylation levels of CtBP factors. Here we show by using proximity ligation assay (PLA) that CtBP2 acetylation levels increased significantly in undifferentiated, proliferating NSCs under hypoxic conditions. CtBP2 interacted with the class III HDAC Sirt1 but this interaction was unaltered in hypoxic conditions, and treatment with the Sirt1 inhibitor Ex527 did not result in any significant change in total CtBP2 acetylation levels. Instead, we revealed a significant decrease in PLA signal representing CtBP2 dimerization in NSCs under hypoxic conditions, negatively correlating with the acetylation levels. Our results suggest that microenvironmental oxygen levels influence the dimerization and acetylation levels, and thereby the activity, of CtBP2 in proliferating NSCs.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Probing electronic wave functions of sodium-doped clusters: Dyson orbitals, anisotropy parameters, and ionization cross-sections

We apply high-level ab initio methods to describe the electronic structure of small clusters of ammonia and dimethylether (DME) doped with sodium, which provide a model for solvated electrons. We investigate the effect of the solvent and cluster size on the electronic states. We consider both energies and properties, with a focus on the shape of the electronic wave function and the related experimental observables such as photoelectron angular distributions. The central quantity in modeling photoionization experiments is the Dyson orbital, which describes the difference between the initial N-electron and final (N-1)-electron states of a system. Dyson orbitals enter the expression of the photoelectron matrix element, which determines total and partial photoionization cross-sections. We compute Dyson orbitals for the Na(NH3)n and Na(DME)m clusters using correlated wave functions (obtained with equation-of-motion coupled-cluster model for electron attachment with single and double substitutions) and compare them with more approximate Hartree-Fock and Kohn-Sham orbitals. As a result, we also analyze the effect of correlation and basis sets on the shapes of Dyson orbitals and the experimental observables.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Geodetic Measurements of Slow-Slip Events Southeast of Parkfield, CA

Tremor and low-frequency earthquakes are presumed to be indicative of surrounding slow, aseismic slip that is often below geodetic detection thresholds. This study uses data from borehole seismometers and long-baseline laser strainmeters to observe both the seismic and geodetic signatures of episodic tremor and slip on the Parkfield region of the San Andreas Fault near Cholame, CA. We note the observed occurrence rates of both the tremors and co-located families of low-frequency earthquakes are not steady but instead exhibit quasiperiodic bursts of increased activity.We show that these periods of elevated seismic activity correlate with statistically significant stacked strain signals consisting of 44 slow-slip events. Modeled individual slow-slip events and their total summed moment, which are constrained by seismic signals and stacked strain, respectively, indicate that the individual moment magnitudes of these events range from $M_w$ 4.6–5.2.We find that the measured geodetic signal likely precedes the seismic signal by several hours, consistent with the aseismic slip preceding and driving the observed seismic tremor activity.We confirm that strike-slip faults, in addition to subduction zones, are capable of producing episodic tremor and slip.

58 GEOSCIENCES↗
DOE OSTI2014

Interstellar protons in the TeV γ-ray SNR HESS J1731-347: Possible evidence for the coexistence of hadronic and leptonic γ-rays

HESS J1731-347 (G353.6-0.7) is one of the TeV γ-ray supernova remnants (SNRs) that shows the shell-like morphology. We have made a new analysis of the interstellar protons toward the SNR by using both the {sup 12}CO(J = 1-0) and H I data sets. The results indicate that the TeV γ-ray shell shows significant spatial correlation with the interstellar protons at a velocity range from –90 km s{sup –1} to –75 km s{sup –1}. The total mass of the interstellar medium (ISM) protons is estimated to be 6.4 × 10{sup 4} M {sub ☉}, 25% of which is atomic gas, and the distance corresponding to the velocity range is ∼5.2 kpc, a factor of 2 larger than the previous figure, 3 kpc. We have identified the cold H I gas observed as self-absorption which shows significant correspondence with the northeastern γ-ray peak. While the good correspondence between the ISM protons and TeV γ-rays in the north of the SNR lends support to the hadronic scenario for the TeV γ-rays, the southern part of the shell shows a break in the correspondence; in particular, the southwestern rim of the SNR shell shows a significant decrease of the interstellar protons by a factor of two. We argue that this discrepancy can be explained due to leptonic γ-rays because this region coincides well with the bright shell that emits non-thermal radio continuum emission and non-thermal X-rays, suggesting that the γ-rays of HESS J1713-347 consist of both the hadronic and leptonic components. The leptonic contribution corresponds to ∼20% of the total γ-rays.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2014

Near-infrared structure of fast and slow-rotating disk galaxies

We investigate the stellar disk structure of six nearby edge-on spiral galaxies using high-resolution JHK {sub s}-band images and three-dimensional radiative transfer models. To explore how mass and environment shape spiral disks, we selected galaxies with rotational velocities between 69 km s{sup –1} 150 km s{sup –1}) galaxies, only NGC 4013 has the super-thin+thin+thick nested disk structure seen in NGC 891 and the Milky Way, albeit with decreased oblateness, while NGC 1055, a disturbed massive spiral galaxy, contains disks with h{sub z} ≲ 200 pc. NGC 4565, another fast-rotator, contains a prominent ring at a radius ∼5 kpc but no super-thin disk. Despite these differences, all fast-rotating galaxies in our sample have inner truncations in at least one of their disks. These truncations lead to Freeman Type II profiles when projected face-on. Slow-rotating galaxies are less complex, lacking inner disk truncations and requiring fewer disk components to reproduce their light distributions. Super-thin disk components in undisturbed disks contribute ∼25% of the total K {sub s}-band light, up to that of the thin-disk contribution. The presence of super-thin disks correlates with infrared flux ratios; galaxies with super-thin disks have f{sub K{sub s}}/f{sub 60} {sub μm}≤0.12 for integrated light, consistent with super-thin disks being regions of ongoing star-formation. Attenuation-corrected vertical color gradients in (J – K {sub s}) correlate with the observed disk structure and are consistent with population gradients with young-to-intermediate ages closer to the mid-plane, indicating that disk heating—or cooling—is a ubiquitous phenomenon.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2015

X-ray emission in non-AGN galaxies at z ≃ 1

Using data from the DEEP2 galaxy redshift survey and the All Wavelength Extended Groth Strip International Survey we obtain stacked X-ray maps of galaxies at 0.7⩽z⩽1.0 as a function of stellar mass. We compute the total X-ray counts of these galaxies and show that in the soft band (0.5–2 kev) there exists a significant correlation between galaxy X-ray counts and stellar mass at these redshifts. The best-fit relation between X-ray counts and stellar mass can be characterized by a power law with a slope of 0.58 ± 0.1. We do not find any correlation between stellar mass and X-ray luminosities in the hard (2–7 kev) and ultra-hard (4–7 kev) bands. The derived hardness ratios of our galaxies suggest that the X-ray emission is degenerate between two spectral models, namely point-like power-law emission and extended plasma emission in the interstellar medium. This is similar to what has been observed in low redshift galaxies. Using a simple spectral model where half of the emission comes from power-law sources and the other half from the extended hot halo we derive the X-ray luminosities of our galaxies. The soft X-ray luminosities of our galaxies lie in the range 10{sup 39}–8×10{sup 40} erg s{sup −1}. Dividing our galaxy sample by the criteria U−B>1, we find no evidence that our results for X-ray scaling relations depend on optical color.

79 ASTRONOMY AND ASTROPHYSICS↗