Dusty star-forming galaxies at high redshift (1 < z < 3) represent the most intense star-forming regions in the universe. Key aspects to these processes are the gas heating and cooling mechanisms, ...and although it is well known that these galaxies are gas-rich, little is known about the gas excitation conditions. Only a few detailed radiative transfer studies have been carried out owing to a lack of multiple line detections per galaxy. Here we examine these processes in a sample of 24 strongly lensed star-forming galaxies identified by the Planck satellite (LPs) at z ∼ 1.1-3.5. We analyze 162 CO rotational transitions (ranging from Jup = 1 to 12) and 37 atomic carbon fine-structure lines (C i) in order to characterize the physical conditions of the gas in the sample of LPs. We simultaneously fit the CO and C i lines and the dust continuum emission, using two different non-LTE, radiative transfer models. The first model represents a two-component gas density, while the second assumes a turbulence-driven lognormal gas density distribution. These LPs are among the most gas-rich, IR-luminous galaxies ever observed ( L L IR ( 8 − 1000 m ) ∼ 10 13 − 14.6 L ; 〈 LMISM 〉 = (2.7 1.2) × 1012 M , with L ∼ 10-30 the average lens magnification factor). Our results suggest that the turbulent interstellar medium present in the LPs can be well characterized by a high turbulent velocity dispersion ( 〈 ΔVturb 〉 ∼ 100 km s−1) and ratios of gas kinetic temperature to dust temperature 〈 Tkin/Td 〉 ∼ 2.5, sustained on scales larger than a few kiloparsecs. We speculate that the average surface density of the molecular gas mass and IR luminosity, M ISM ∼ 103-4 M pc−2 and L IR ∼ 1011-12 L kpc−2, arise from both stellar mechanical feedback and a steady momentum injection from the accretion of intergalactic gas.
While the chemotherapeutic effect of curcumin, one of three major curcuminoids derived from turmeric, has been reported, largely unexplored are the effects of complex turmeric extracts more analogous ...to traditional medicinal preparations, as well as the relative importance of the three curcuminoids and their metabolites as anti-cancer agents. These studies document the pharmacodynamic effects of chemically-complex turmeric extracts relative to curcuminoids on human breast cancer cell growth and tumor cell secretion of parathyroid hormone-related protein (PTHrP), an important driver of cancer bone metastasis. Finally, relative effects of structurallyrelated metabolites of curcuminoids were assessed on the same endpoints. We report that 3 curcuminoid-containing turmeric extracts differing with respect to the inclusion of additional naturally occurring chemicals (essential oils and/or polar compounds) were equipotent in inhibiting human breast cancer MDA-MB-231 cell growth (IC50=10-16µg/mL) and secretion of osteolytic PTHrP (IC50=2-3µg/mL) when concentrations were normalized to curcuminoid content. Moreover, these effects were curcuminoid-specific, as botanically-related gingerol containing extracts had no effect. While curcumin and bis-demethoxycurcumin were equipotent to each other and to the naturally occurring curcuminoid mixture (IC50=58µM), demethoxycurcumin did not have any effect on cell growth. However, each of the individual curcuminoids inhibited PTHrP secretion (IC50=22-31µM) to the same degree as the curcuminoid mixture (IC50=16µM). Degradative curcuminoid metabolites (vanillin and ferulic acid) did not inhibit cell growth or PTHrP, while reduced metabolites (tetrahydrocurcuminoids) had inhibitory effects on cell growth and PTHrP secretion but only at concentrations ≥10-fold higher than the curcuminoids. These studies emphasize the structural and biological importance of curcuminoids in the anti-breast cancer effects of turmeric and contradict recent assertions that certain of the curcuminoid metabolites studied here mediate these anti-cancer effects.
We model the strong lensing effect in the galaxy cluster PSZ1 G311.65-18.48 (
z
= 0.443) with an improved version of the hybrid method WSLAP+. We extend the number of constraints by including the ...position of critical points, which are combined with the classic positional constraints of the lensed galaxies. We pay special attention to a transient candidate source (Tr) previously discovered in the giant Sunburst arc (
z
= 2.37). Our lens model predicts Tr to be within a fraction of an arcsecond from the critical curve, which has a larger magnification factor than previously found, but still not large enough to explain the observed flux and lack of counterimages. Possible candidate counterimages are discussed that would lower the magnification required to explain Tr, but extreme magnification factors (
μ
> 600) are still required, even in that case. The presence of a small mass perturber with a mass comparable to a dwarf galaxy (
M
∼ 10
8
M
⊙
) near the position of Tr is needed in order to explain the required magnification and morphology of the lensed galaxy. We discuss how the existence of this perturber could potentially be used to constrain models of dark matter. The large apparent brightness and unresolved nature of the magnified object implies a combination of extreme magnification and a very luminous and compact source (
r
< 0.4 pc). Possible candidates are discussed, including an hyperluminous star, a small group of stars, or an accretion disk around a relatively small supermassive black hole (SMBH). Based on spectral information and flux requirements, we argue that a luminous blue variable (LBV) star caught during an outburst is the most likely candidate. Owing to the extreme magnification and luminosity of this source, we dub it Godzilla.
The
Planck
satellite has identified more than 2000 protocluster candidates with extreme star formation rates (SFRs). Here, we present the spectroscopic identification of a
Planck
-selected ...protocluster located in the Cosmos field, PHz G237.01+42.50. PHz G237.01+42.50 contains a galaxy overdensity of 31 spectroscopically identified galaxies at
z
≃ 2.16 (significant at 5.4
σ
) in a 10′ × 11′ region. The overdensity contains two substructures or protoclusters at ⟨
z
⟩ ≃ 2.16 and 2.195 with estimated halo masses at
z
= 0 of ∼5–6 × 10
14
M
⊙
, roughly consistent with Virgo-type clusters. The overdensity total SFR, ∼4000
M
⊙
yr
−1
, is higher than predicted by simulations but much smaller than the SFR derived from the
Planck
data (i.e., 10 173
M
⊙
yr
−1
). The analysis of the
Herschel
data in the field, in combination with the available ancillary data, shows that such a difference is due to an effect of source alignment along the line of sight that produces a 5
σ
overdensity of red
Herschel
sources in the field. We analyze the members’ ultraviolet (UV) spectra and UV-far-infrared spectral energy distributions to derive their SFR, stellar mass, and metallicity. Galaxy members include blue star-forming galaxies and Active galactic nuclei (AGN) with SFRs and stellar masses consistent with the main sequence. Active galactic nuclei, identified through optical spectroscopy or X-ray data, represent a significant fraction (20 ± 10%) of all members of the protocluster at
z
= 2.16, and they are powerful enough to produce radiative feedback. The core of this protocluster, besides being denser, includes members that are, on average, more massive and star-forming and contains a larger fraction of AGN and
Herschel
-detected galaxies than the full sample, suggesting an environmental effect on galaxy growth. A comparison between PHz G237.01+42.50 and other protoclusters in the literature at similar redshifts reveals some common traits and differences that reflect both observational biases and a diversity in intrinsic properties that is not yet fully understood.
We present a detailed strong-lensing, weak-lensing and X-ray analysis of Abell 2744 (z= 0.308), one of the most actively merging galaxy clusters known. It appears to have unleashed 'dark', 'ghost', ...'bullet' and 'stripped' substructures, each ∼1014 M⊙. The phenomenology is complex and will present a challenge for numerical simulations to reproduce. With new, multiband Hubble Space Telescope (HST) imaging, we identify 34 strongly lensed images of 11 galaxies around the massive Southern 'core'. Combining this with weak-lensing data from HST, VLT and Subaru, we produce the most detailed mass map of this cluster to date. We also perform an independent analysis of archival Chandra X-ray imaging. Our analyses support a recent claim that the Southern core and Northwestern substructure are post-merger and exhibit morphology similar to the Bullet Cluster viewed from an angle. From the separation between X-ray emitting gas and lensing mass in the Southern core, we derive a new and independent constraint on the self-interaction cross-section of dark matter particles σ/m < 3 ± 1 cm2 g−1. In the Northwestern substructure, the gas, dark matter and galaxy components have become separated by much larger distances. Most curiously, the 'ghost' clump (primarily gas) leads the 'dark' clump (primarily dark matter) by more than 150 kpc. We propose an enhanced 'ram-pressure slingshot' scenario which may have yielded this reversal of components with such a large separation, but needs further confirmation by follow-up observations and numerical simulations. A secondary merger involves a second 'bullet' clump in the North and an extremely 'stripped' clump to the West. The latter appears to exhibit the largest separation between dark matter and X-ray emitting baryons detected to date in our sky.
There is a lack of large samples of spectroscopically confirmed clusters and protoclusters at high redshifts, z > 1.5. Discovering and characterizing distant (proto-)clusters is important for ...yielding insights into the formation of large-scale structure and on the physical processes responsible for regulating star-formation in galaxies in dense environments. The Spitzer Planck Herschel Infrared Cluster (SPHerIC) survey was initiated to identify these characteristically faint and dust-reddened sources during the epoch of their early assembly. We present Spitzer/IRAC observations of 82 galaxy (proto-)cluster candidates at 1.3 < zp < 3.0 that were vetted in a two step process: (1) using Planck to select by color those sources with the highest star-formation rates, and (2) using Herschel at higher resolution to separate out the individual red sources. The addition of the Spitzer data enables efficient detection of the central and massive brightest red cluster galaxies (BRCGs). We find that BRCGs are associated with highly significant, extended and crowded regions of IRAC sources which are more overdense than the field. This result corroborates our hypothesis that BRCGs within the Planck–Herschel sources trace some of the densest and actively star-forming proto-clusters in the early Universe. On the basis of a richness-mass proxy relation, we obtain an estimate of their mean masses which suggests our sample consists of some of the most massive clusters at z ≈ 2 and are the likely progenitors of the most massive clusters observed today.
Paleogenetics is an emerging field that resurrects ancestral proteins from now-extinct organisms to test, in the laboratory, models of protein function based on natural history and Darwinian ...evolution. Here, we resurrect digestive alcohol dehydrogenases (ADH4) from our primate ancestors to explore the history of primate–ethanol interactions. The evolving catalytic properties of these resurrected enzymes show that our ape ancestors gained a digestive dehydrogenase enzyme capable of metabolizing ethanol near the time that they began using the forest floor, about 10 million y ago. The ADH4 enzyme in our more ancient and arboreal ancestors did not efficiently oxidize ethanol. This change suggests that exposure to dietary sources of ethanol increased in hominids during the early stages of our adaptation to a terrestrial lifestyle. Because fruit collected from the forest floor is expected to contain higher concentrations of fermenting yeast and ethanol than similar fruits hanging on trees, this transition may also be the first time our ancestors were exposed to (and adapted to) substantial amounts of dietary ethanol.
Significance Many modern human diseases are attributed to incompatibility between our current environment and the environment for which our genome is adapted. It is unclear whether this model applies to alcoholism. We investigated this possibility by studying alcohol dehydrogenase class IV (ADH4), the first enzyme exposed to ethanol in the digestive tract that is capable of metabolizing ethanol. We resurrected ancestral ADH4 enzymes from various points in the ∼70 million y of primate evolution and identified a single mutation occurring ∼10 million y ago that endowed our ancestors with a markedly enhanced ability to metabolize ethanol. This change occurred approximately when our ancestors adopted a terrestrial lifestyle and may have been advantageous to primates living where highly fermented fruit is more likely.
We present a detailed mass reconstruction and a novel study on the substructure properties in the core of the Cluster Lensing And Supernova survey with Hubble (CLASH) and Frontier Fields galaxy ...clusterMACS J0416.1-2403. We reproduce the measured positions of a set of 30 multiple images with a remarkable median offset of only 0.3 by means of a comprehensive strong lensing model comprised of two cluster dark-matter halos, represented by cored elliptical pseudo-isothermal mass distributions, and the cluster member components, parameterized with dual pseudo-isothermal total mass profiles. We investigate the galaxy contribution, both in terms of total and stellar mass, to the total mass budget of the cluster. Our findings of the location and shape of the cluster dark-matter halo density profiles and on the cluster substructures provide intriguing tests of the assumed collisionless, cold nature of dark matter and of the role played by baryons in the process of structure formation.
We present an analysis of CO spectroscopy and infrared-to-millimetre dust photometry of 11 exceptionally bright far-infrared (FIR) and sub-mm sources discovered through a combination of the Planck ...all-sky survey and follow-up Herschel-SPIRE imaging – “Planck’s Dusty Gravitationally Enhanced subMillimetre Sources”. Each source has a secure spectroscopic redshift z = 2.2–3.6 from multiple lines obtained through a blind redshift search with EMIR at the IRAM 30-m telescope. Interferometry was obtained at IRAM and the SMA, and along with optical/near-infrared imaging obtained at the CFHT and the VLT reveal morphologies consistent with strongly gravitationally lensed sources, including several giant arcs. Additional photometry was obtained with JCMT/SCUBA-2 and IRAM/GISMO at 850 μm and 2 mm, respectively. The SEDs of our sources peak near either the 350 μm or 500 μm bands of SPIRE with peak flux densities between 0.35 and 1.14 Jy. All objects are extremely bright isolated point sources in the 18′′ beam of SPIREat 250 μm, with apparent FIR luminosities of up to 3 × 1014 L⊙ (not correcting for the lensing effect). Their morphologies, sizes, CO line widths, CO luminosities, dust temperatures, and FIR luminosities provide additional empirical evidence that these are amongst the brightest strongly gravitationally lensed high-redshift galaxies on the sub-mm sky. Our programme extends the successful wide-area searches for strongly gravitationally lensed high-redshift galaxies (carried out with the South Pole Telescope and Herschel) towards even brighter sources, which are so rare that their systematic identification requires a genuine all-sky survey like Planck. Six sources are above the ≃600 mJy 90% completeness limit of the Planck catalogue of compact sources (PCCS) at 545 and 857 GHz, which implies that these must literally be amongst the brightest high-redshift FIR and sub-mm sources on the extragalactic sky. We discuss their dust masses and temperatures, and use additional WISE 22-μm photometry and template fitting to rule out a significant contribution of AGN heating to the total infrared luminosity. Six sources are detected in FIRST at 1.4 GHz, and the others have sensitive upper limits. Four have flux densities brighter than expected from the local FIR-radio correlation, but in the range previously found for high-z sub-mm galaxies, one has a deficit of FIR emission, and 6 are consistent with the local correlation, although this includes 3 galaxies with upper limits. We attribute this to the turbulent interstellar medium of these galaxies, rather than the presence of radio AGN. The global dust-to-gas ratios and star-formation efficiencies of our sources are predominantly in the range expected from massive, metal-rich, intense, high-redshift starbursts. An extensive multi-wavelength follow-up programme is being carried out to further characterize these sources and the intense star formation within them.
Aims. We perform a comprehensive study of the total mass distribution of the galaxy cluster RXC J2248.7−4431 (z = 0.348) with a set of high-precision strong lensing models, which take advantage of ...extensive spectroscopic information on many multiply lensed systems. In the effort to understand and quantify inherent systematics in parametric strong lensing modelling, we explore a collection of 22 models in which we use different samples of multiple image families, different parametrizations of the mass distribution and cosmological parameters. Methods. As input information for the strong lensing models, we use the Cluster Lensing And Supernova survey with Hubble (CLASH) imaging data and spectroscopic follow-up observations, with the VIsible Multi-Object Spectrograph (VIMOS) and Multi Unit Spectroscopic Explorer (MUSE) on the Very Large Telescope (VLT), to identify and characterize bona fide multiple image families and measure their redshifts down to mF814W ≃ 26. A total of 16 background sources, over the redshift range 1.0−6.1, are multiply lensed into 47 images, 24 of which are spectroscopically confirmed and belong to ten individual sources. These also include a multiply lensed Lyman-α blob at z = 3.118. The cluster total mass distribution and underlying cosmology in the models are optimized by matching the observed positions of the multiple images on the lens plane. Bayesian Markov chain Monte Carlo techniques are used to quantify errors and covariances of the best-fit parameters. Results. We show that with a careful selection of a large sample of spectroscopically confirmed multiple images, the best-fit model can reproduce their observed positions with a rms scatter of 0.̋3 in a fixed flat ΛCDM cosmology, whereas the lack of spectroscopic information or the use of inaccurate photometric redshifts can lead to biases in the values of the model parameters. We find that the best-fit parametrization for the cluster total mass distribution is composed of an elliptical pseudo-isothermal mass distribution with a significant core for the overall cluster halo and truncated pseudo-isothermal mass profiles for the cluster galaxies. We show that by adding bona fide photometric-selected multiple images to the sample of spectroscopic families, one can slightly improve constraints on the model parameters. In particular, we find that the degeneracy between the lens total mass distribution and the underlying geometry of the Universe, which is probed via angular diameter distance ratios between the lens and sources and the observer and sources, can be partially removed. Allowing cosmological parameters to vary together with the cluster parameters, we find (at 68% confidence level) Ωm = 0.25+ 0.13-0.16 and w = −1.07+ 0.16-0.42 for a flat ΛCDM model, and Ωm = 0.31+ 0.12-0.13 and ΩΛ = 0.38+ 0.38-0.27 for a Universe with w = −1 and free curvature. Finally, using toy models mimicking the overall configuration of multiple images and cluster total mass distribution, we estimate the impact of the line-of-sight mass structure on the positional rms to be 0.̋3 ± 0. We argue that the apparent sensitivity of our lensing model to cosmography is due to the combination of the regular potential shape of RXC J2248, a large number of bona fide multiple images out to z = 6.1, and a relatively modest presence of intervening large-scale structure, as revealed by our spectroscopic survey.
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