Gas dynamics of a luminous zz = 6.13 quasar ULAS J1319++0950 revealed by ALMA high resolution observations

We present new Atacama Large Millimeter/submillimeter Array (ALMA) observations of the dust continuum and [C II] 158 $\mu$m fine structure line emission towards a far-infrared-luminous quasar, ULAS J131911.29$+$095051.4 at $z=6.13$, and combine the new Cycle 1 data with ALMA Cycle 0 data. The combined data have an angular resolution $\sim$ $0.3$, and resolve both the dust continuum and the [C II] line emission on few kpc scales. The [C II] line emission is more irregular than the dust continuum emission which suggests different distributions between the dust and [C II]-emitting gas. The combined data confirm the [C II] velocity gradient that we previously detected in lower resolution ALMA image from Cycle 0 data alone. We apply a tilted ring model to the [C II] velocity map to obtain a rotation curve, and constrain the circular velocity to be 427 $\pm$ 55 km s$^{-1}$ at a radius of 3.2 kpc with an inclination angle of 34$^\circ$. We measure the dynamical mass within the 3.2 kpc region to be 13.4$_{-5.3}^{+7.8}$ $\times 10^{10}\,M_{\odot}$. This yields a black hole and host galaxy mass ratio of 0.020$_{-0.007}^{+0.013}$, which is about 4$_{-2}^{+3}$ times higher than the present-day $M_{\rm BH}$/$M_{\rm bulge}$ ratio. This suggests that the supermassive black hole grows the bulk of its mass before the formation of the most of stellar mass in this quasar host galaxy in the early universe.Comment: 24 pages, 5 figures, accepted for publication in Ap

Observations by GMRT at 323 MHz of radio-loud quasars at z>5z>5

We present Giant Metrewave Radio Telescope (GMRT) 323 MHz radio continuum observations toward 13 radio-loud quasars at $z>5$, sampling the low-frequency synchrotron emission from these objects. Among the 12 targets successfully observed, we detected 10 above $4\sigma$ significance, while 2 remain undetected. All of the detected sources appear as point sources. Combined with previous radio continuum detections from the literature, 9 quasars have power-law spectral energy distributions throughout the radio range; for some the flux density drops with increasing frequency while it increases for others. Two of these sources appear to have spectral turnover. For the power-law-like sources, the power-law indices have a positive range between 0.18 and 0.67 and a negative values between $-0.90$ and $-0.27$. For the turnover sources, the radio peaks around $\sim1$ and $\sim10$ GHz in the rest frame, the optically thin indices are $-0.58$ and $-0.90$, and the optically thick indices are 0.50 and 1.20. A magnetic field and spectral age analysis of SDSS J114657.59+403708.6 at $z=5.01$ may indicate that the turnover is not caused by synchrotron self-absorption, but rather by free-free absorption by the high-density medium in the nuclear region. Alternatively, the apparent turnover may be an artifact of source variability. Finally, we calculated the radio loudness $R_{2500\rm\, \AA}$ for our sample, which spans a very wide range from 12$^{+13}_{-13}$ to 4982$^{+279}_{-254}$.Comment: 13 pages; Accepted by A&

High-free Fatty Acid Treatment Induced Anti-inflammatory Changes in a Natural Killer (NK) Cell Line

Background: Natural killer (NK) cells play a role in the pathogenesis of various metabolic diseases related to obesity. While our initial findings have indicated a potential involvement of NK cells in the pathogenesis of type 2 diabetes mellitus, the precise mechanism underlying NK cell-mediated development of this form of diabetes remains inadequately comprehended.Objective: To investigate the impact and the underlying mechanism of high glucose and elevated levels of free fatty acids (FFAs) on immune and inflammatory responses and oxidative stress in NK92 cells.Methods: In this experiment, the CCK8 cytotoxicity assay was used to select the 44.4 mM and 1.5 mM concentrations of high glucose and high FFAs, respectively, to treat NK92 cells for 4 days. The concentrations of superoxide dismutase (SOD) and glutathione (GSH) were determined using a biochemical analyzer. Intracellular reactive oxygen species (ROS) levels, cytokines concentrations (TNF-α, IFN-γ, IL-6, and IL-10), and the expression levels of intracellular molecules (perforin and granzyme B) were assessed by flow cytometry.Results: The number of NK92 cell clumps was significantly reduced in the high-FFA (HF) group. In addition, the production of ROS and levels of cytokines (TNF-α, IFN-γ, IL-6, and IL-10) significantly decreased in the HF group but showed no significant change in the high-glucose (HG) group. This observation was consistent with the expression levels of perforin and granzyme B that decreased in the HF group.Conclusion: High FFAs induced morphological changes and serious damage to oxidative stress and inflammatory response in NK92 cells

SCUBA2 High Redshift Bright Quasar Survey: Far-infrared Properties and Weak-line Features

We present a submillimetre continuum survey ('SCUBA2 High rEdshift bRight quasaR surveY', hereafter SHERRY) of 54 high redshift quasars at $5.6<z<6.9$ with quasar bolometric luminosities in a range of (0.2$-$$5)\times10^{14}\,L_{\odot}$, using the Submillimetre Common-User Bolometer Array-2 (SCUBA2) on the James Clerk Maxwell Telescope. About 30% (16/54) of the sources are detected with a typical 850$\mu$m rms sensitivity of 1.2 $\rm mJy\,beam^{-1}$ ($S\rm _{\nu,850\,\mu m} = 4$-5 mJy, at $>3.5\sigma$). The new SHERRY detections indicate far-infrared (FIR) luminosities of $\rm 3.5\times10^{12}$ to $\rm 1.4\times10^{13}$ $L_{\odot}$, implying extreme star formation rates of 90 to 1060 $M_{\odot}$ yr$^{-1}$ in the quasar host galaxies. Compared with $z =$ 2$-$5 samples, the FIR luminous quasars ($L_{\rm FIR} > 10^{13}\,L_{\odot}$) are more rare at $z \sim 6$. The optical/near-infrared (NIR) spectra of these objects show 11% (6/54) of the sources have weak Ly$\alpha$, emission line features, which may relate to different sub-phases of the central active galactic nuclei (AGNs). Our SCUBA2 survey confirms the trend reported in the literature that quasars with submillimeter detections tend to have weaker ultraviolet (UV) emission lines compared to quasars with nondetections. The connection between weak UV quasar line emission and bright dust continuum emission powered by massive star formation may suggest an early phase of AGN-galaxy evolution, in which the broad line region is starting to develop slowly or is shielded from the central ionization source, and has unusual properties such as weak line features or bright FIR emission.Comment: 28 pages, 10 figures, published in Ap

The interstellar medium distribution, gas kinematics, and system dynamics of the far-infrared luminous quasar SDSS J2310+1855 at z=6.0z=6.0

We present ALMA sub-kpc- to kpc-scale resolution observations of the [CII], CO(9-8), and OH$^{+}$\,($1_{1}$--$0_{1}$) lines along with their dust continuum emission toward the FIR luminous quasar SDSS J231038.88+185519.7 at $z = 6.0031$. The [CII] brightness follows a flat distribution with a Sersic index of 0.59. The CO(9-8) line and the dust continuum can be fit with an unresolved nuclear component and an extended Sersic component with a Sersic index of ~1. The dust temperature drops with distance from the center. The effective radius of the dust continuum is smaller than that of the line emission and the dust mass surface density, but is consistent with that of the star formation rate surface density. The OH$^{+}$\,($1_{1}$--$0_{1}$) line shows a P-Cygni profile with an absorption, which may indicate an outflow with a neutral gas mass of $(6.2\pm1.2)\times10^{8} M_{\odot}$ along the line of sight. We employed a 3D tilted ring model to fit the [CII] and CO(9-8) data cubes. The two lines are both rotation dominated and trace identical disk geometries and gas motions. We decompose the circular rotation curve measured from the kinematic model fit to the [CII] line into four matter components (black hole, stars, gas, and dark matter). The quasar-starburst system is dominated by baryonic matter inside the central few kiloparsecs. We constrain the black hole mass to be $2.97^{+0.51}_{-0.77}\times 10^{9}\,M_{\odot}$; this is the first time that the dynamical mass of a black hole has been measured at $z\sim6$. A massive stellar component (on the order of $10^{9}\,M_{\odot}$) may have already existed when the Universe was only ~0.93 Gyr old. The relations between the black hole mass and the baryonic mass of this quasar indicate that the central supermassive black hole may have formed before its host galaxy. [Abridged version. Please see the full abstract in the manuscript.]Comment: Accepted for publication in A&

(SHERRY) JCMT-SCUBA2 High Redshift Bright Quasar Survey -- II: the environment of z~6 quasars in sub-millimeter band

The formation of the first supermassive black holes is expected to have occurred in some most pronounced matter and galaxy overdensities in the early universe. We have conducted a sub-mm wavelength continuum survey of 54 $z\sim6$ quasars using the Submillimeter Common-User Bolometre Array-2 (SCUBA2) on the James Clerk Maxwell Telescope (JCMT) to study the environments around $z \sim 6$ quasars. We identified 170 submillimeter galaxies (SMGs) with above 3.5$\sigma$ detections at 450 or 850 \um\, maps. Their FIR luminosities are 2.2 - 6.4 $\times$ 10$^{12} L_{\odot}$, and star formation rates are $\sim$ 400 - 1200 M$_{\odot}$ yr$^{-1}$. We also calculated the SMGs differential and cumulative number counts in a combined area of $\sim$ 620 arcmin$^2$. To a $4\sigma$ detection (at $\sim$ 5.5 mJy), SMGs overdensity is $0.68^{+0.21}_{-0.19}$($\pm0.19$), exceeding the blank field source counts by a factor of 1.68. We find that 13/54 quasars show overdensities (at $\sim$ 5.5 mJy) of $\delta_{SMG}\sim$ 1.5 - 5.4. The combined area of these 13 quasars exceeds the blank field counts with the overdensity to 5.5 mJy of \dsmg $\sim$ $2.46^{+0.64}_{-0.55}$($\pm0.25$) in the regions of $\sim$ 150 arcmin$^2$. However, the excess is insignificant on the bright end (e.g., 7.5 mJy). We also compare results with previous environmental studies of Lyman alpha emitters (LAEs) and Lyman-Break Galaxies (LBGs) on a similar scale. Our survey presents the first systematic study of the environment of quasars at $z\sim6$. The newly discovered SMGs provide essential candidates for follow-up spectroscopic observations to test whether they reside in the same large-scale structures as the quasars and search for protoclusters at an early epoch.Comment: 12 pages, 8 figures and 2 tables, accepted for publication in Ap

Helminth infection protects against high fat diet-induced obesity via induction of alternatively activated macrophages

Epidemiological studies indicate an inverse correlation between the prevalence of the so-called western diseases, such as obesity and metabolic syndrome, and the exposure to helminths. Obesity, a key risk factor for many chronic health problems, is rising globally and is accompanied by low-grade inflammation in adipose tissues. The precise mechanism by which helminths modulate metabolic syndrome and obesity is not fully understood. We infected high fat diet (HFD)-induced obese mice with the intestinal nematode parasite Heligmosomoides polygyrus and observed that helminth infection resulted in significantly attenuated obesity. Attenuated obesity corresponded with marked upregulation of uncoupling protein 1 (UCP1), a key protein involved in energy expenditure, in adipose tissue, suppression of glucose and triglyceride levels, and alteration in the expression of key genes involved in lipid metabolism. Moreover, the attenuated obesity in infected mice was associated with enhanced helminth-induced Th2/Treg responses and M2 macrophage polarization. Adoptive transfer of helminth-stimulated M2 cells to mice that were not infected with H. polygyrus resulted in a significant amelioration of HFD-induced obesity and increased adipose tissue browning. Thus, our results provide evidence that the helminth-dependent protection against obesity involves the induction of M2 macrophages