ABSTRACT The central structure in three of the brightest unlensed z = 3-4 submillimeter galaxies is investigated through 0 015-0 05 (120-360 pc) 860 m continuum images obtained using the Atacama ...Large Millimeter/submillimeter Array (ALMA). The distribution in the central kiloparsec in AzTEC1 and AzTEC8 is extremely complex, and they are composed of multiple ∼200 pc clumps. AzTEC4 consists of two sources that are separated by ∼1.5 kpc, indicating a mid-stage merger. The peak star formation rate densities in the central clumps are ∼300-3000 M yr−1 kpc−2, suggesting regions with extreme star formation near the Eddington limit. By comparing the flux obtained by ALMA and Submillimeter Array, we find that 68%-90% of the emission is extended ( 1 kpc) in AzTEC4 and 8. For AzTEC1, we identify at least 11 additional compact (∼200 pc) clumps in the extended 3-4 kpc region. Overall, the data presented here suggest that the luminosity surface densities observed at 150 pc scales are roughly similar to that observed in local ULIRGs, as in the eastern nucleus of Arp 220. Between 10% and 30% of the 860 m continuum is concentrated in clumpy structures in the central kiloparsec, while the remaining flux is distributed over 1 kpc regions, some of which could also be clumpy. These sources can be explained by a rapid inflow of gas such as a merger of gas-rich galaxies, surrounded by extended and clumpy starbursts. However, the cold mode accretion model is not ruled out.
One of the determinants for tissue tropism of hepatitis C virus (HCV) is miR-122, a liver-specific microRNA. Recently, it has been reported that interaction of miR-122 to HCV RNA induces a ...conformational change of the 5’UTR internal ribosome entry site (IRES) structure to form stem-loop II structure (SLII) and hijack of translating 80S ribosome through the binding of SLIII to 40S subunit, which leads to efficient translation. On the other hand, low levels of HCV-RNA replication have also been detected in some non-hepatic cells; however, the details of extrahepatic replication remain unknown. These observations suggest the possibility that miRNAs other than miR-122 can support efficient replication of HCV-RNA in non-hepatic cells. Here, we identified a number of such miRNAs and show that they could be divided into two groups: those that bind HCV-RNA at two locations (miR-122 binding sites I and II), in a manner similar to miR-122 (miR-122-like), and those that target a single site that bridges sites I and II and masking both G28 and C29 in the 5’UTR (non-miR-122-like). Although the enhancing activity of these non-hepatic miRNAs were lower than those of miR-122, substantial expression was detected in various normal tissues. Furthermore, structural modeling indicated that both miR-122-like and non-miR-122-like miRNAs not only can facilitate the formation of an HCV IRES SLII but also can stabilize IRES 3D structure in order to facilitate binding of SLIII to the ribosome. Together, these results suggest that HCV facilitates miR-122-independent replication in non-hepatic cells through recruitment of miRNAs other than miR-122. And our findings can provide a more detailed mechanism of miR-122-dependent enhancement of HCV-RNA translation by focusing on IRES tertiary structure.
Discovery of Merging Twin Quasars at z = 6.05 Matsuoka, Yoshiki; Izumi, Takuma; Onoue, Masafusa ...
Astrophysical journal. Letters,
04/2024, Letnik:
965, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Abstract We report the discovery of two quasars at a redshift of z = 6.05 in the process of merging. They were serendipitously discovered from the deep multiband imaging data collected by the Hyper ...Suprime-Cam (HSC) Subaru Strategic Program survey. The quasars, HSC J121503.42−014858.7 (C1) and HSC J121503.55−014859.3 (C2), both have luminous (>10 43 erg s −1 ) Ly α emission with a clear broad component (full width at half maximum >1000 km s −1 ). The rest-frame ultraviolet (UV) absolute magnitudes are M 1450 = − 23.106 ± 0.017 (C1) and −22.662 ± 0.024 (C2). Our crude estimates of the black hole masses provide log ( M BH / M ⊙ ) = 8.1 ± 0.3 in both sources. The two quasars are separated by 12 kpc in projected proper distance, bridged by a structure in the rest-UV light suggesting that they are undergoing a merger. This pair is one of the most distant merging quasars reported to date, providing crucial insight into galaxy and black hole build-up in the hierarchical structure formation scenario. A companion paper will present the gas and dust properties captured by Atacama Large Millimeter/submillimeter Array observations, which provide additional evidence for and detailed measurements of the merger, and also demonstrate that the two sources are not gravitationally lensed images of a single quasar.
Abstract
We present Atacama Large Millimeter/submillimeter Array C
ii
158
μ
m line and far-infrared (FIR) continuum emission observations toward HSC J120505.09−000027.9 (J1205−0000) at
z
= 6.72 with ...a beam size of ∼0.″8 × 0.″5 (or 4.1 kpc × 2.6 kpc), the most distant red quasar known to date. Red quasars are modestly reddened by dust and are thought to be in rapid transition from an obscured starburst to an unobscured normal quasar, driven by powerful active galactic nucleus (AGN) feedback that blows out a cocoon of interstellar medium. The FIR continuum of J1205−0000 is bright, with an estimated luminosity of
L
FIR
∼ 3 × 10
12
L
⊙
. The C
ii
line emission is extended on scales of
r
∼ 5 kpc, greater than that of the FIR continuum. The line profiles at the extended regions are complex and broad (FWHM ∼ 630–780 km s
−1
). Although it is not practical to identify the nature of this extended structure, possible explanations include (i) companion/merging galaxies and (ii) massive AGN-driven outflows. For the case of (i), the companions are modestly star-forming (∼10
M
⊙
yr
−1
) but are not detected by our Subaru optical observations (
y
AB,5
σ
= 24.4 mag). For the case of (ii), our lower limit to the cold neutral outflow rate is ∼100
M
⊙
yr
−1
. The outflow kinetic energy and momentum are both much lower than predicted in energy-conserving wind models, suggesting that the AGN feedback in this quasar is not capable of completely suppressing its star formation.
We present the results of a blind millimeter line emitter search using ALMA Band 6 data with a single-frequency tuning toward four gravitational lensing clusters (RXJ1347.5−1145, Abell S0592, MACS ...J0416.1−2403, and Abell 2744). We construct 3D signal-to-noise ratio (S/N) cubes with 60 and 100 MHz binning, and search for millimeter line emitters. We do not detect any line emitters with a peak S/N > 5, although we do find a line emitter candidate with a peak S/N 4.5. These results provide upper limits to the CO(3−2), CO(4−3), CO(5−4), and C ii luminosity functions at z 0.3, 0.7, 1.2, and 6, respectively. Because of the magnification effect of gravitational lensing clusters, the new data provide the first constraints on the CO and C ii luminosity functions at unprecedentedly low luminosity levels, i.e., down to 10−3 - 10−1 Mpc−3 dex−1 at K km s−1 pc2 and 10−3-10−2 Mpc−3 dex−1 at , respectively. Although the constraints to date are not yet stringent, we find that the evolution of the CO and C ii luminosity functions are broadly consistent with the predictions of semi-analytical models. This study demonstrates that the wide observations with a single-frequency tuning toward gravitational lensing clusters are promising for constraining the CO and C ii luminosity functions.
ABSTRACT
As part of the Measuring Black Holes in below Milky Way-mass (M⋆) galaxies (MBHBM⋆) Project, we present a dynamical measurement of the supermassive black hole (SMBH) mass in the nearby ...lenticular galaxy NGC 3593, using cold molecular gas 12CO(2-1) emission observed at an angular resolution of ≈0${_{.}^{\prime\prime}}$3 (≈10 pc) with the Atacama Large Millimeter/submillimeter Array (ALMA). Our ALMA observations reveal a circumnuclear molecular gas disc (CND) elongated along the galaxy major axis and rotating around the SMBH. This CND has a relatively low-velocity dispersion (≲10 km s−1) and is morphologically complex, with clumps having higher integrated intensities and velocity dispersions (≲25 km s−1). These clumps are distributed along the ridges of a two-arm/bi-symmetric spiral pattern surrounded by a larger ring-like structure (radius r ≈ 10 arcsec or ≈350 pc). This pattern likely plays an important role to bridge the molecular gas reservoirs in the CND and beyond (10 ≲ r ≲ 35 arcsec or 350 pc ≲ r ≲ 1.2 kpc). Using dynamical modelling, the molecular gas kinematics allow us to infer an SMBH mass $M_{\rm BH}=2.40_{-1.05}^{+1.87}\times 10^6$ M⊙ (only statistical uncertainties at the 3σ level). We also detect a massive core of cold molecular gas (CMC) of mass MCMC = (5.4 ± 1.2) × 106 M⊙ and effective (half-mass) radius rCMC,e = 11.2 ± 2.8 pc, co-spatial with a nuclear star cluster (NSC) of mass MNSC = (1.67 ± 0.48) × 107 M⊙ and effective radius rNSC,e = 5.0 ± 1.0 pc (or 0${_{.}^{\prime\prime}}$15 ± 0${_{.}^{\prime\prime}}$03). The mass profiles of the CMC and NSC are well described by Sérsic functions with indices 1−1.4. Our MBH and MNSC estimates for NGC 3593 agree well with the recently compiled MBH–MNSC scaling relation. Although the MNSC uncertainty is twice the inferred MBH, the rapid central rise of the rotation velocities of the CND (as the radius decreases) clearly suggests an SMBH. Indeed, our dynamical models show that even if MNSC is at the upper end of its allowed range, the evidence for a BH does not vanish, but remains with a lower limit of MBH > 3 × 105 M⊙.
Abstract
Background
This study aimed to determine which running pattern of the left gastric vein (LGV) is most frequently ligated in subtotal stomach-preserving pancreatoduodenectomy (SSPPD) and how ...LGV ligation affects delayed gastric emptying (DGE) after SSPPD.
Methods
We retrospectively analysed 105 patients who underwent SSPPD between January 2016 and September 2021. We classified the running pattern of LGV as follows: type 1 runs dorsal to the common hepatic artery (CHA) or splenic artery (SpA) to join the portal vein (PV), type 2 runs dorsal to the CHA or SpA and joins the splenic vein, type 3 runs ventral to the CHA or SpA and joins the PV, and type 4 runs ventral to the CHA or SpA and joins the SpV. Univariate and multivariate analyses were used to identify differences between patients with and without DGE after SSPPD.
Results
Type 1 LGV running pattern was observed in 47 cases (44.8%), type 2 in 23 (21.9%), type 3 in 12 (11.4%), and type 4 in 23 (21.9%). The ligation rate was significantly higher in type 3 (75.0%) LGVs (
p
< 0.0001). Preoperative obstructive jaundice (
p
= 0.0306), LGV ligation (
p
< 0.0001), grade B or C pancreatic fistula (
p
= 0.0116), and sepsis (
p
= 0.0123) were risk factors for DGE in the univariate analysis. Multivariate analysis showed that LGV ligation was an independent risk factor for DGE (odds ratio: 13.60, 95% confidence interval: 3.80–48.68,
p
< 0.0001).
Conclusion
Type 3 LGVs are often ligated because they impede lymph node dissection; however, LGV preservation may reduce the occurrence of DGE after SSPPD.
Abstract
We present a catalog of the millimeter-wave (mm-wave) continuum properties of 98 nearby (
z
< 0.05) active galactic nuclei (AGNs) selected from the 70 month Swift/BAT hard-X-ray catalog that ...have precisely determined X-ray spectral properties and subarcsecond-resolution Atacama Large Millimeter/submillimeter Array Band 6 (211–275 GHz) observations as of 2021 April. Due to the hard-X-ray (>10 keV) selection, the sample is nearly unbiased for obscured systems at least up to Compton-thick-level obscuration, and provides the largest number of AGNs with high-physical-resolution mm-wave data (≲100–200 pc). Our catalog reports emission peak coordinates, spectral indices, and peak fluxes and luminosities at 1.3 mm (230 GHz). Additionally, high-resolution mm-wave images are provided. Using the images and creating radial surface brightness profiles of mm-wave emission, we identify emission extending from the central sources and isolated blob-like emission. Flags indicating the presence of these emission features are tabulated. Among 90 AGNs with significant detections of nuclear emission, 37 AGNs (≈41%) appear to have both or one of extended or blob-like components. We, in particular, investigate AGNs that show well-resolved mm-wave components and find that these seem to have a variety of origins (i.e., a jet, radio lobes, a secondary AGN, stellar clusters, a narrow-line region, galaxy disk, active star formation regions, or AGN-driven outflows), and some components have currently unclear origins.
We report the study of the far-infrared (IR) sizes of submillimeter galaxies (SMGs) in relation to their dust-obscured star formation rate (SFR) and active galactic nuclei (AGN) presence, determined ...using mid-IR photometry. We determined the millimeter-wave ( m) sizes of 69 Atacama Large Millimeter/submillimeter Array (ALMA)-identified SMGs, selected with confidence on ALMA images ( -7.4 mJy). We found that all of the SMGs are located above an avoidance region in the size-flux plane, as expected by the Eddington limit for star formation. In order to understand what drives the different millimeter-wave sizes in SMGs, we investigated the relation between millimeter-wave size and AGN fraction for 25 of our SMGs at z = 1-3. We found that the SMGs for which the mid-IR emission is dominated by star formation or AGN have extended millimeter-sizes, with respective median and kpc. Instead, the SMGs for which the mid-IR emission corresponds to star-forming/AGN composites have more compact millimeter-wave sizes, with median kpc. The relation between millimeter-wave size and AGN fraction suggests that this size may be related to the evolutionary stage of the SMG. The very compact sizes for composite star-forming/AGN systems could be explained by supermassive black holes growing rapidly during the SMG coalescing, star-formation phase.
Background
Acute mediastinitis is a rare disease that rapidly progresses with a high mortality rate. Its most common cause is direct injury of the mediastinum, including iatrogenic causes such as ...cardiac surgery or upper endoscopy. Enzymatic mediastinitis is a rare complication of a pancreatic fistula caused by the inflammatory digestion of the parietal peritoneum spreading to the mediastinum. Here, we present two cases of enzymatic mediastinitis caused by total gastrectomy with splenectomy. One of them was successfully treated and cured after early diagnosis and transabdominal drainage.
Case presentation
Case 1 was that of a 60-year-old man (body mass index BMI 27) with a medical history of diabetes and hypertension who was diagnosed with advanced gastric cancer in the upper body of the stomach. A total gastrectomy with splenectomy was performed. The patient experienced acute respiratory failure 24 h after surgery. Pulmonary embolism was suspected, so a computed tomography (CT) scan was performed; however, no relevant causes were found. Although he was immediately intubated and treated with catecholamine, he died in the intensive care unit (ICU) 40 h after surgery. Post-mortem findings revealed retroperitonitis caused by a pancreatic fistula spreading towards the mediastinum, causing severe mediastinitis; a review of the CT scan revealed pneumomediastinum. We concluded that the cause of death was enzymatic mediastinitis due to post-gastrectomy pancreatic fistula. Case 2 involved a 61-year-old man (BMI 25) with a medical history of appendicitis who was diagnosed with advanced gastric cancer at the gastric angle between the lesser curvature and the pylorus, spreading to the upper body of the stomach. A total gastrectomy with splenectomy was also performed. The patient had a high fever 3 days after the surgery, and a CT scan revealed pneumomediastinum, indicating mediastinitis. As the inflammation was below the bronchial bifurcation, we chose a transabdominal approach for drainage. The patient was successfully treated and discharged.
Conclusion
Acute mediastinitis caused by gastrectomy is rare. The acknowledgment of abdominal surgery as a cause of mediastinitis is important. In treating mediastinitis caused by abdominal surgery, transabdominal drainage may be a minimally invasive yet effective method if the inflammation is mainly located below the bifurcation of the trachea.
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