Over several decades, near infrared (NIR) diffuse reflectance spectroscopy (NIRS) has been shown to be extremely versatile for the rapid analysis of many agricultural materials including forages, ...foods and grains. More recently, mid-infrared (mid-IR) diffuse reflectance spectroscopy (DRIFTS) and NIRS have come under intense scrutiny for their potential to provide a rapid method for the analysis of soil C, minerals and other soil parameters of interest. Research has demonstrated that for the determination of soil C, DRIFTS is often more accurate and produces more robust calibrations than NIRS when analyzing ground, dry soils under laboratory conditions. However, mid-IR spectra are known to be more affected by moisture and sample preparation than NIR. In reality, DRIFTS is not even considered feasible on samples containing high levels of moisture due to the strong water absorptions in the mid-IR, although the presence of water is also known to often degrade even NIR spectra and subsequent calibrations. While both techniques offer the potential for the analysis of soils on-site, and even in situ, many questions remain to be answered including: 1. What are the advantages and disadvantages of on-site as opposed to laboratory analysis? 2. What are the effects of moisture and particle size on accuracy if samples are to be analyzed on-site? 3. Which spectral range (mid-IR or NIR) is the most effective for in laboratory and/or on-site analysis? 4. Which analytes can be accurately analyzed by NIR and/or mid-IR spectroscopy? 5. What are the effects of different soil types and compositions on the entire process of calibration development? In addition, while DRIFTS has been shown to be advantageous in the laboratory, if samples need to be ground and dried, and instruments purged to obtain useable data, it may not be practical for on-site use. This review will try to answer some of these questions and show where the science stands and what needs to be done before NIRS or DRIFTS can be fully exploited for routine soil analysis.
Abstract
The quasar PDS 456 (at redshift ∼0.184) has a prototype ultra-fast outflow (UFO) measured in X-rays. This outflow is highly ionized with relativistic speeds, large total column densities log ...NH(cm−2) > 23, and large kinetic energies that could be important for feedback to the host galaxy. A UV spectrum of PDS 456 obtained with the Hubble Space Telescope in 2000 contains one well-measured broad absorption line (BAL) at ∼1346 Å (observed) that might be Ly α at v ≈ 0.06c or N v λ1240 at v ≈ 0.08c. However, we use photoionization models and comparisons to other outflow quasars to show that these BAL identifications are problematic because other lines that should accompany them are not detected. We argue that the UV BAL is probably C iv at v ≈ 0.30c. This would be the fastest UV outflow ever reported, but its speed is similar to the X-ray outflow and its appearance overall is similar to relativistic UV BALs observed in other quasars. The C iv BAL identification is also supported indirectly by the tentative detection of another broad C iv line at v ≈ 0.19c. The high speeds suggest that the UV outflow originates with the X-ray UFO crudely 20–30 rg from the central black hole. We speculate that the C iv BAL might form in dense clumps embedded in the X-ray UFO, requiring density enhancements of only ≳0.4 dex compared to clumpy structures already inferred for the soft X-ray absorber in PDS 456. The C iv BAL might therefore be the first detection of low-ionization clumps proposed previously to boost the opacities in UFOs for radiative driving.
We present the results of a new spectroscopic study of Fe K-band absorption in active galactic nuclei (AGN). Using data obtained from the Suzaku public archive we have performed a statistically ...driven blind search for Fe xxv Heα and/or Fe xxvi Lyα absorption lines in a large sample of 51 Type 1.0-1.9 AGN. Through extensive Monte Carlo simulations we find that statistically significant absorption is detected at E 6.7 keV in 20/51 sources at the P
MC ≥ 95 per cent level, which corresponds to ∼40 per cent of the total sample. In all cases, individual absorption lines are detected independently and simultaneously amongst the two (or three) available X-ray imaging spectrometer detectors, which confirms the robustness of the line detections. The most frequently observed outflow phenomenology consists of two discrete absorption troughs corresponding to Fe xxv Heα and Fe xxvi Lyα at a common velocity shift. From xstar fitting the mean column density and ionization parameter for the Fe K absorption components are log (N
H/cm−2) 23 and log (ξ/erg cm s−1) 4.5, respectively. Measured outflow velocities span a continuous range from <1500 km s−1 up to ∼100 000 km s−1, with mean and median values of ∼0.1 c and ∼0.056 c, respectively. The results of this work are consistent with those recently obtained using XMM-Newton and independently provides strong evidence for the existence of very highly ionized circumnuclear material in a significant fraction of both radio-quiet and radio-loud AGN in the local universe.
There has been an increasing interest in the use of mid-infrared spectroscopy for the quantitative analysis of soils. Understanding the spectral bands can be beneficial both for understanding the ...basis of the quantitative analysis and soil composition and structure in general. Unfortunately, at least from the standpoint of the organic composition of soils, the spectra of most soils are dominated by the spectra of inorganic fractions such as clays, silica, carbonates, etc. One method used to accentuate the signature of the organic fraction has been to ash soil samples and then use spectral subtraction, in theory leaving only the spectral signature of the organic fraction. The objective of this work was to investigate exactly how accurate/practical this procedure is and is derived from recent comments from reviewers. Results examining silt, clays, silica, calcium carbonate, soils and materials such as cellulose and lignin show that, without considerable prior knowledge of a soil sample, spectral interpretation in most regions of the mid-infrared is highly interpretive/subjective at best. While the region for CH absorptions (3000–2800cm−1) is free of interferences, except for carbonates which can be removed by acidification, and the region between 1750–1600cm−1 can be interpreted despite the presence of strong silica bands, interpretation of the remaining regions of the mid-infrared are deemed very subjective. This is largely, but not entirely, due to the fact that many types of clay undergo extreme spectral changes from ashing and materials with seemingly similar formulas such as kaolinite (Al2Si2O5(OH)4) and pyrophyllite (Al2Si4O10(OH)2) change differently when ashed. Thus unless one knows the exact clay/mineral composition of the soil in question and the effects of ashing on said clay/mineral, accurately interpreting the ash subtracted spectra is nearly impossible. Also, even subtracting silica was found to be difficult due to changing specular effects even with KBr diluted samples. From a practical standpoint, one must conclude that the routine use of ash subtraction is not practical for soils as too much needs to be known to judge the results.
► Spectral subtraction of ash to highlight organic matter found to be highly risky. ► Changes in clays during ashed make it mimic changes in organic matter. ► Spectral subtraction thus only practical for limit region of the mid-IR. ► Specular changes in silica with ashing also problematic. ► Dilution with KBr does not help to any great degree due to clays.
We present Atacama Large Millimetre/submillimetre Array (ALMA) CO(1–0) observations of the nearby infrared luminous (LIRG) galaxy pair IRAS 05054+1718 (also known as CGCG 468-002), as well as a new ...analysis of X-ray data of this source collected between 2012 and 2021 using the Nuclear Spectroscopic Telescope Array (
NuSTAR
),
Swift
, and the
XMM-Newton
satellites. The western component of the pair, NED01, hosts a Seyfert 1.9 nucleus that is responsible for launching a powerful X-ray ultra-fast outflow (UFO). Our X-ray spectral analysis suggests that the UFO could be variable or multi-component in velocity, ranging from
v
/
c
∼ −0.12 (as seen in
Swift
) to
v
/
c
∼ −0.23 (as seen in
NuSTAR
), and constrains its momentum flux to be
ṗ
out
X−ray
∼ (4 ± 2) × 10
34
g cm s
−2
. The ALMA CO(1–0) observations, obtained with an angular resolution of 2.2″, although targeting mainly NED01, also include the eastern component of the pair, NED02, a less-studied LIRG with no clear evidence of an active galactic nucleus (AGN). We study the CO(1–0) kinematics in the two galaxies using the 3D-BAROLO code. In both sources we can model the bulk of the CO(1–0) emission with rotating disks and, after subtracting the best-fit models, we detect compact residual emission at
S
/
N
= 15 within ∼3 kpc of the centre. A molecular outflow in NED01, if present, cannot be brighter than such residuals, implying an upper limit on its outflow rate of
Ṁ
out
mol
≲ 19 ± 14
M
⊙
yr
−1
and on its momentum rate of
ṗ
out
mol
≲ (2.7 ± 2.4) × 10
34
g cm s
−1
. Combined with the revised energetics of the X-ray wind, we derive an upper limit on the momentum rate ratio of
ṗ
out
mol
/
ṗ
out
X−ray
< 0.67. We discuss these results in the context of the expectations of AGN feedback models, and we propose that the X-ray disk wind in NED01 has not significantly impacted the molecular gas reservoir (yet), and we can constrain its effect to be much smaller than expectations of AGN ‘energy-driven’ feedback models. We also consider and discuss the hypothesis of asymmetries of the molecular disk not properly captured by the 3D-BAROLO code. Our results highlight the challenges in testing the predictions of popular AGN disk-wind feedback theories, even in the presence of good-quality multi-wavelength observations.
We describe results from IMmotion150, a randomized phase 2 study of atezolizumab (anti-PD-L1) alone or combined with bevacizumab (anti-VEGF) versus sunitinib in 305 patients with treatment-naive ...metastatic renal cell carcinoma. Co-primary endpoints were progression-free survival (PFS) in intent-to-treat and PD-L1+ populations. Intent-to-treat PFS hazard ratios for atezolizumab + bevacizumab or atezolizumab monotherapy versus sunitinib were 1.0 (95% confidence interval (CI), 0.69-1.45) and 1.19 (95% CI, 0.82-1.71), respectively; PD-L1+ PFS hazard ratios were 0.64 (95% CI, 0.38-1.08) and 1.03 (95% CI, 0.63-1.67), respectively. Exploratory biomarker analyses indicated that tumor mutation and neoantigen burden were not associated with PFS. Angiogenesis, T-effector/IFN-γ response, and myeloid inflammatory gene expression signatures were strongly and differentially associated with PFS within and across the treatments. These molecular profiles suggest that prediction of outcomes with anti-VEGF and immunotherapy may be possible and offer mechanistic insights into how blocking VEGF may overcome resistance to immune checkpoint blockade.
The presence of an obscuring torus at parsec-scale distances from the central black hole is the main ingredient for the Unified Model of active galactic nuclei (AGN), as obscured sources are thought ...to be seen through this structure. However, the Unified Model fails to describe a class of sources that undergo dramatic spectral changes, transitioning from obscured to unobscured and vice versa through time. The variability in these sources, which are known as changing-look AGN (CLAGN), is thought to be produced by a clumpy medium at much smaller distances than the conventional obscuring torus. ESO 323-G77 is a CLAGN that was observed in various states through the years with
Chandra
, Suzaku,
Swift
-XRT, and
XMM-Newton
, from unobscured (
N
H
< 3 × 10
22
cm
−2
) to Compton-thin (
N
H
∼ 1 − 6 × 10
23
cm
−2
) and even Compton-thick (
N
H
> 1 × 10
24
cm
−2
), on timescales as short as one month. We present an analysis of the first NuSTAR monitoring of ESO 323-G77, consisting of five observations taken at different timescales (1, 2, 4, and 8 weeks from the first one) in 2016–2017, in which the AGN was caught in a persistent Compton-thin obscured state (
N
H
∼ 2 − 4 × 10
23
cm
−2
). We find that a Compton-thick reflector is present (
N
H, refl
= 5 × 10
24
cm
−2
), most likely associated with the presence of the putative torus. Two ionized absorbers are unequivocally present, located within maximum radii of
r
max, 1
= 1.5 pc and
r
max, 2
= 0.01 pc. In one of the observations, the inner ionized absorber is blueshifted, indicating the presence of a possible faster (
v
out
= 0.2
c
) ionized absorber, marginally detected at 3
σ
. Finally, we are able to constrain the coronal temperature and the optical depth of ESO 323-G77, obtaining
kT
e
= 38 keV or
kT
e
= 36 keV, and
τ
= 1.4 or
τ
= 2.8, depending on the coronal geometry assumed.
We performed mid-infrared (MidIR) spectral interpretation of fractionated fresh and incubated soils to determine changes in soil organic matter (SOM) chemistry during incubation. Soils from four ...sites and three depths were processed to obtain the light fraction (LF), particulate organic matter (POM), silt-sized (silt), and clay-sized (clay) fractions. Our results show that the LF and clay fractions have distinct spectral features regardless of site. The LF is characterized by absorbance at 3400 cm−1, as well as between 1750 and 1350 cm−1 The clay fraction is distinguished by absorption near 1230 cm−1, and absorption at 780 to 620 cm−1 The POM, like the LF, absorbs at the broad peak at 1360 cm−1 High SOM soils are characterized by absorbance at 1230 cm−1, a band for aromatics, possibly associated with resistant C. Soils from different sampling depths have specific spectral properties. A band at 1330 cm−1 is characteristic of shallow depths. Because of their low organic matter (OM) content, the deeper samples are characterized by mineral bands such as quartz, clays, and carbonate. Spectroscopic data indicates that the clay fraction and the LF suffered measurable chemical transformations during the 800-d incubation, but the POM and silt fraction did not. As the LF decomposes, it loses absorbance at 3400, 1223, and 2920 to 2860 cm−1 The band at 1630 cm−1 increased during incubation, suggesting a resistant form of organic C. The clay fraction suffered changes that were opposite to those of the LF, indicating that LF decomposition and clay decomposition follow different chemistries.
Abstract Studying the behavior along the galaxy main sequence is key in furthering our understanding of the possible connection between active galactic nucleus (AGN) activity and star formation. We ...select a sample of 1215 AGN from the catalog of Sloan Digital Sky Survey galaxy properties from the Portsmouth group by detection of the high-ionization Ne v 3426 Å emission line. Our sample extends from 10 40 to 10 42.5 erg s −1 in Ne v luminosity in a redshift range z = 0.17 to 0.57. We compare the specific star formation rates (sSFRs; SFR scaled by galaxy mass) obtained from the corrected O ii and H α luminosities, and the spectral energy distribution (SED)–determined values from Portsmouth. We find that the emission-line-based sSFR values are unreliable for the Ne v sample due to the AGN contribution, and proceed with the SED sSFRs for our study of the main sequence. We find evidence for a decrease in sSFR along the main sequence in the Ne v sample, which is consistent with results from the hard X-ray Burst Alert Telescope AGN sample, which extends to lower redshifts than our Ne v sample. Although we do not find evidence that the concurrent AGN activity is suppressing star formation, our results are consistent with a lower gas fraction in the host galaxies of the AGN as compared to that of the star-forming galaxies. If the evacuation of gas, and therefore suppression of star formation, is due to AGN activity, it must have occurred in a previous epoch.
Abstract We select a sample of 1437 active galactic nuclei (AGN) from the catalog of the Sloan Digital Sky Survey galaxy properties from the Portsmouth group by detection of the high-ionization Ne v ...3426 Å emission line. We compare the fluxes of Ne III 3869 Å, O III 5007 Å, O II 3726, 3728 Å, and O i 6300 Å to that of Ne v. All four lines show a strong linear correlation with Ne v, although lines from ions with lower ionization potentials have a lower correlation coefficient. We investigate the use of two forbidden line ratio diagnostic diagrams that do not rely on H α in order to classify high-redshift galaxies. These use the Ne III /O II line ratio plotted against O III /O i and O III /O II , respectively. We use photoionization modeling to characterize the behavior of the narrow-line region in AGN and star-forming regions and test the validity of our diagnostic diagrams. We also use a luminosity cutoff of log L O III erg s −1 = 42, which lowers the contamination of the AGN region by star-forming galaxies down to 10% but does not remove green pea and purple grape galaxies from the AGN region. We also investigate the OHNO diagram, which uses Ne III /O II plotted against O III /H β . Using our new diagnostic diagrams, we are able to reliably classify AGN up to a redshift of z ≤ 1.06 and add more than 822 new AGN to the Ne v-selected AGN sample.
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