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Odd radio circles (ORCs) are a newly discovered class of extended faint radio sources of unknown origin. We report the first detection of diffuse X-ray gas at the location of a low-redshift ORC (z = 0.046) known as Cloverleaf ORC. This observation was performed with the XMM-Newton X-ray telescope. The physical extent of the diffuse X-ray emission corresponds to a region of approximately 230 kpc by 160 kpc, lying perpendicular to the radio emission detected by ASKAP. The X-ray spectrum shows characteristics of thermal multiphase gas with temperatures of 1.10 ± 0.08 keV and 0.22 ± 0.01 keV and a central density of (4.9 ± 0.6)×10−4 cm−3, indicating that the Cloverleaf ORC resides in a low-mass galaxy group. Using X-ray observations, with hydrostatic equilibrium and isothermal assumptions, we measure the galaxy group to have a gas mass and a total mass of (7.7 ± 0.8)×1011 M⊙ and 2.6 ± 0.3 × 1013 M⊙ within the overdensity radius R500. The presence of a high-velocity subgroup identified in optical data, the orientation of the brightest cluster galaxy, the disturbed morphologies of galaxies toward the east of the Cloverleaf ORC, and the irregular morphology of the X-ray emission suggest that this system is undergoing a galaxy group merger. The radio power of the ORC could be explained by the shock reacceleration of fossil cosmic rays generated by a previous episode of black hole activity in the central active galactic nucleus. [ABSTRACT FROM AUTHOR]

The paper presents the analysis of optically selected GAMA groups and clusters in the SRG/eROSITA X-ray map of eROSITA Final Equatorial Depth Survey, in the halo mass range 1013−5 × 1014 M⊙ and at z < 0.2. All X-ray detections have a clear GAMA counterpart, but most of the GAMA groups in the halo mass range 1013−1014 M⊙ remain undetected. We compare the X-ray surface brightness profiles of the eROSITA detected groups with the mean stacked profile of the undetected low-mass haloes at fixed halo mass. Overall, we find that the undetected groups exhibit less concentrated X-ray surface brightness, dark matter, and galaxy distributions with respect to the X-ray-detected haloes. The mean gas mass fraction profiles are consistent in the two samples within 1.5σ, indicating that the gas follows the dark matter profile. The low-mass concentration and the magnitude gap indicate that these systems are young. They reside with a higher probability in filaments while X-ray-detected groups favour the nodes of the Cosmic Web. Because of the lower central emission, the undetected systems tend to be X-ray underluminous at fixed halo mass and to lie below the LX − M halo relation. Interestingly, the X-ray-detected systems inhabiting the nodes scatter the less around the relation, while those in filaments tend to lie below it. We do not observe any strong relationship between the system X-ray appearance and the active galactic nucleus (AGN) activity. We cannot exclude the role of the past AGN feedback in affecting the gas distribution over the halo lifetime. However, the data suggests that the observed differences might be related to the halo assembly bias. [ABSTRACT FROM AUTHOR]

We report the first statistical detection of X-ray emission from cosmic web filaments in ROSAT data. We selected 15 165 filaments at 0.2 <  z <  0.6 ranging from 30 Mpc to 100 Mpc in length, identified in the Sloan Digital Sky Survey survey. We stacked the X-ray count-rate maps from ROSAT around the filaments, excluding resolved galaxy groups and clusters above the mass of ∼3 × 1013 M⊙ as well as the detected X-ray point sources from the ROSAT, Chandra, and XMM-Newton observations. The stacked signal results in the detection of the X-ray emission from the cosmic filaments at a significance of 4.2σ in the energy band of 0.56−1.21 keV. The signal is interpreted, assuming the Astrophysical Plasma Emission Code model, as an emission from the hot gas in the filament-core regions with an average gas temperature of 0.9−0.6+1.0 0. 9 − 0.6 + 1.0 $ 0.9^{+1.0}_{-0.6} $ keV and a gas overdensity of δ ∼ 30 at the center of the filaments. Furthermore, we show that stacking the SRG/eROSITA data for ∼2000 filaments only would lead to a ≳5σ detection of their X-ray signal, even with an average gas temperature as low as ∼0.3 keV. [ABSTRACT FROM AUTHOR]

The variation of galaxy stellar masses and colour types with the distance to projected cosmic filaments are quantified using the precise photometric redshifts of the COSMOS2015 catalogue extracted from Cosmological Evolution Survey (COSMOS) field (2 deg2). Realistic mock catalogues are also extracted from the lightcone of the cosmological hydrodynamical simulation Horizon-AGN. They show that the photometric redshift accuracy of the observed catalogue (σz < 0.015 at M* > 1010M⊙ and z < 0.9) is sufficient to provide two-dimensional (2D) filaments that closely match their projected three-dimensional (3D) counterparts. Transverse stellar mass gradients are measured in projected slices of thickness 75 Mpc between 0.5 < z < 0.9, showing that the most massive galaxies are statistically closer to their neighbouring filament. At fixed stellar mass, passive galaxies are also found closer to their filament, while active star-forming galaxies statistically lie further away. The contributions of nodes and local density are removed from these gradients to highlight the specific role played by the geometry of the filaments. We find that the measured signal does persist after this removal, clearly demonstrating that proximity to a filament is not equivalent to proximity to an overdensity. These findings are in agreement with gradients measured in both 2D and 3D in the Horizon-AGN simulation and those observed in the spectroscopic surveys VIPERS and GAMA (which both rely on the identification of 3D filaments). They are consistent with a picture in which the influence of the geometry of the large-scale environment drives anisotropic tides that impact the assembly history of galaxies, and hence their observed properties. [ABSTRACT FROM AUTHOR]

The role of the cosmic web in shaping galaxy properties is investigated in the Galaxy And Mass Assembly (GAMA) spectroscopic survey in the redshift range 0.03 ≤ z ≤ 0.25. The stellar mass, u - r dust corrected colour and specific star formation rate (sSFR) of galaxies are analysed as a function of their distances to the 3Dcosmic web features, such as nodes, filaments and walls, as reconstructed by DisPerSE. Significant mass and type/colour gradients are found for the whole population, with more massive and/or passive galaxies being located closer to the filament and wall than their less massive and/or star-forming counterparts. Mass segregation persists among the star-forming population alone. The red fraction of galaxies increases when closing in on nodes, and on filaments regardless of the distance to nodes. Similarly, the starforming population reddens (or lowers its sSFR) at fixed mass when closing in on filament, implying that some quenching takes place. These trends are also found in the state-of-the-art hydrodynamical simulation HORIZON-AGN. These results suggest that on top of stellar mass and large-scale density, the traceless component of the tides from the anisotropic large-scale environment also shapes galactic properties. An extension of excursion theory accounting for filamentary tides provides a qualitative explanation in terms of anisotropic assembly bias: at a given mass, the accretion rate varies with the orientation and distance to filaments. It also explains the absence of type/colour gradients in the data on smaller, non-linear scales. [ABSTRACT FROM AUTHOR]

We present the first quantitative detection of large-scale filamentary structure at z ≃ 0.7 in the large cosmological volume probed by the VIMOS Public Extragalactic Redshift Survey (VIPERS).We use simulations to show the capability of VIPERS to recover robust topological features in the galaxy distribution, in particular the filamentary network. We then investigate how galaxies with different stellar masses and stellar activities are distributed around the filaments, and find a significant segregation, with the most massive or quiescent galaxies being closer to the filament axis than less massive or active galaxies. The signal persists even after downweighting the contribution of peak regions. Our results suggest that massive and quiescent galaxies assemble their stellar mass through successive mergers during their migration along filaments towards the nodes of the cosmic web. On the other hand, low-mass star-forming galaxies prefer the outer edge of filaments, a vorticity-rich region dominated by smooth accretion, as predicted by the recent spin alignment theory. This emphasizes the role of large-scale cosmic flows in shaping galaxy properties. [ABSTRACT FROM AUTHOR]

Background: In patients with colorectal liver metastases (CLM) R0 resection significantly improves overall survival (OS).Methods: In this report, we present the results of a phase II trial of FOLFOX6+bevacizumab in patients with non-optimally resectable CLM. Patients received six cycles of FOLFOX6+ five of bevacizumab. Patients not achieving resectability received six additional cycles of each. A PET-CT was performed at baseline and again within 1 month after initiating treatment.Results: From September 2005 to July 2009, 21 patients were enrolled (Male/Female: 15/6; median age: 65 years). An objective response (OR) was documented in 12 cases (57.1%; complete responses (CRs): 3, partial response (PR): 9); one patient died from toxicity before surgery. Thirteen patients underwent radical surgery (61.9%). Three (23%) had a pathological CR (pCR). Six patients (46.1%) experienced minor postsurgical complications. After a median 38.8-month follow-up, the median OS was 22.5 months. Patients achieving at least 1 unit reduction in Standard uptake value (SUV)max on PET-CT had longer progression-free survival (PFS) (median PFS: 22 vs 14 months, P=0.001).Conclusions: FOLFOX6+bevacizumab does not increase postsurgical complications, yields high rates of resectability and pCR. Early changes in PET-CT seem to be predictive of longer PFS. [ABSTRACT FROM AUTHOR]

Background: Epidermal growth factor receptor (EGFR), evaluated by immunohistochemistry, has been shown to have prognostic significance in patients with colorectal cancer. Gene copy number (GCN) of EGFR and KRAS status predict response and outcome in patients treated with anti-EGFR therapy, but their prognostic significance in colorectal cancer patients is still unclear.Methods: We have retrospectively reviewed the baseline EGFR GCN, KRAS status and clinical outcome of 146 locally advanced rectal cancer (LARC) patients treated with preoperative chemoradiotherapy. Pathological response evaluated by Dworak's tumour regression grade (TRG), disease-free survival (DFS) and overall survival (OS) were analysed.Results: Tumour regression grade 4 and TRG3-4 were achieved in 14.4 and 30.8% of the patients respectively. Twenty-nine (19.9%) and 33 patients (19.2%) had an EGFR/nuclei ratio >2.9 and CEP7 polisomy >50% respectively; 28 patients (19.2%) had a KRAS mutation. Neither EGFR GCN nor KRAS status was statistically correlated to TRG. 5-year DFS and OS were 63.3 and 71.5%, respectively, and no significant relation with EGFR GCN or KRAS status was found.Conclusion: Our data show that EGFR GCN and KRAS status are not prognostic factors in LARC treated with preoperative chemoradiation. [ABSTRACT FROM AUTHOR]

Background: Advanced biliary tract carcinoma has a very poor prognosis, with chemotherapy being the mainstay of treatment. Sorafenib, a multikinase inhibitor of VEGFR-2/-3, PDGFR-beta, B-Raf, and C-Raf, has shown to be active in preclinical models of cholangiocarcinoma.Methods: We conducted a phase II trial of single-agent sorafenib in patients with advanced biliary tract carcinoma. Sorafenib was administered at a dose of 400 mg twice a day. The primary end point was the disease control rate at 12 weeks.Results: A total of 46 patients were treated. In all, 26 (56%) had received chemotherapy earlier, and 36 patients completed at least 45 days of treatment. In intention-to-treat analysis, the objective response was 2% and the disease control rate at 12 weeks was 32.6%. Progression-free survival (PFS) was 2.3 months (range: 0-12 months), and the median overall survival was 4.4 months (range: 0-22 months). Performance status was significantly related to PFS: median PFS values for ECOG 0 and 1 were 5.7 and 2.1 months, respectively (P=0.0002). The most common toxicities were skin rash (35%) and fatigue (33%), requiring a dose reduction in 22% of patients.Conclusions: Sorafenib as a single agent has a low activity in cholangiocarcinoma. Patients having a good performance status have a better PFS. The toxicity profile is manageable. [ABSTRACT FROM AUTHOR]

We investigate the effect of the environment on the Faber-Jackson (FJ) relation, using a sample of 384 nearby elliptical galaxies and estimating objectively their environment on the typical scale of galaxy clusters. We show that the intrinsic scatter of the FJ relation is significantly reduced when ellipticals in high-density environments are compared to ellipticals in low-density ones. This result, which holds in a limited range of overdensities, is likely to provide an important observational link between scaling relations and formation mechanisms in galaxies. [ABSTRACT FROM AUTHOR]