Search

We compared the molecular clouds in the western part of SS 433 with near-ultraviolet radiation data obtained from GALEX. Near-ultraviolet radiation is prominently confirmed toward only N4, while no near-ultraviolet radiation is detected toward N1, N2, and N3. The radiative region of near-ultraviolet radiation is nearly the same as the CO-emitting region in N4, and does not extend beyond the jet seen in X-ray radiation. Near-ultraviolet radiation cannot be explained solely by broadband continuous radiation and may originate from line emissions. The intensity of near-ultraviolet radiation exhibits an anti-correlation with that of 13CO(J=3-2) emission. This anti-correlation, along with strong far-infrared radiation in the region with weaker near-ultraviolet radiation intensity compared to its surroundings, suggests that near-ultraviolet radiation originates from behind the molecular cloud, heating up the interstellar dust in N4. Subsequently, the dust in N4 re-radiates in the far-infrared band. In the same region, a high peak T_MB ratio of 12CO(J=3-2)/12CO(J=1-0) of ~0.9, and a high kinetic temperature of T_k ~56 K in the molecular cloud indicate that CO molecules are highly excited, and the molecular cloud is heated through photoelectric heating. This heating results from electrons released due to the photoelectric effect caused by the phenomenon where interstellar dust absorbs near-ultraviolet radiation. In terms of the timescale of near-ultraviolet radiation originating from line emissions, near-ultraviolet radiation towards N4 cannot be explained by the shock of the blast wave from a supernova that created W 50. These findings also suggest that N4 directly interacts with the jet from SS 433. As a result of this direct interaction, near-ultraviolet radiation is emitted from an interacting layer between the jet and N4., Comment: 16 pages, 7 figures, Accepted for publication in PASJ

Understanding how galaxies quench their star formation is crucial for studies of galaxy evolution. Quenching is related to the cold gas decrease. In the first paper we showed that the dust removal timescale in early-type galaxies (ETGs) is about 2.5 Gyr. Here we present carbon monoxide (CO) and 21 cm hydrogen (H I) line observations of these galaxies and measure the timescale of removal of the cold interstellar medium (ISM). We find that all the cold ISM components (dust, molecular and atomic gas) decline at similar rates. This allows us to rule out a wide range of potential ISM removal mechanisms (including starburst-driven outflows, astration, a decline in the number of asymptotic giant branch stars), and artificial effects like stellar mass-age correlation, environmental influence, mergers, and selection bias, leaving ionization by evolved low-mass stars and ionization/outflows by supernovae Type Ia or active galactic nuclei as viable mechanisms. We also provide evidence for an internal origin of the detected ISM. Moreover, we find that the quenching of star formation in these galaxies cannot be explained by a reduction in gas amount alone, because the star formation rates (SFRs) decrease faster (on a timescale of about 1.8 Gyr) than the amount of cold gas. Furthermore, the star formation efficiency of the ETGs (SFE = SFR/MH2) is lower than that of star-forming galaxies, whereas their gas mass fractions (fH2 = MH2/M*) are normal. This may be explained by the stabilization of gas against fragmentation, for example due to morphological quenching, turbulence, or magnetic fields., Comment: Astrophysical Journal, published; 29 pages, 13 figures, 6 tables; V2: matched the published version and typos in the SFR and outflow equations fixed - no change in the conclusions

Context. The Galactic centre is hazardous for stellar clusters because of the strong tidal force. Supposedly, many clusters were destroyed and contributed stars to the crowded stellar field of the bulge and the nuclear stellar cluster. However, it is hard to develop a realistic model to predict the long-term evolution of the complex inner Galaxy, and observing surviving clusters in the central region would provide crucial insights into destruction processes. Aims. Among hitherto-known Galactic globular clusters, VVV CL002 is the closest to the centre, 0.4 kpc, but has a very high transverse velocity, 400 km s$^{-1}$. The nature of this cluster and its impact on Galactic astronomy need to be addressed with spectroscopic follow-up. Methods. Here we report the first measurements of its radial velocity and chemical abundance based on near-infrared high-resolution spectroscopy. Results. We found that this cluster has a counterrotating orbit constrained within 1.0\,kpc of the centre, as close as 0.2 kpc at the perigalacticon, confirming that the cluster is not a passerby from the halo but a genuine survivor enduring the harsh conditions of the Galactic mill's tidal forces. In addition, its metallicity and $\alpha$ abundance ([$\alpha$/Fe] $\simeq +0.4$ and [Fe/H]$=-0.54$) are similar to some globular clusters in the bulge. Recent studies suggest that stars with such $\alpha$-enhanced stars were more common at 3 - 6 kpc from the centre around 10 Gyrs ago. Conclusions. We infer that VVV CL002 was formed outside but is currently falling down to the centre, exhibiting a real-time event that must have occurred to many clusters a long time ago., Comment: Contains 6 pages with 6 figures. Accepted for publication in Astronomy & Astrophysics

We aim to understand what drives the IRX-\beta dust attenuation relation at intermediate redshift (0.5 < z < 0.8) in star-forming galaxies. We investigate the role of various galaxy properties in shaping this observed relation. We use robust [O ii] {\lambda}3727, [O iii] {\lambda}{\lambda}4959, 5007, and H\beta line detections of our statistical sample of 1049 galaxies to estimate the gas-phase metallicities. We derive key physical properties that are necessary to study galaxy evolution, such as the stellar masses and the star formation rates, using the spectral energy distribution fitting tool CIGALE. Equivalently, we study the effect of galaxy morphology (mainly the S\'ersic index n and galaxy inclination) on the observed IRX-\beta scatter. We also investigate the role of the environment in shaping dust attenuation in our sample. We find a strong correlation of the IRX-\beta relation on gas-phase metallicity in our sample, and also strong correlation with galaxy compactness characterized by the S\'ersic indexes. Correlations are also seen with stellar masses, specific star formation rates and the stellar ages of our sources. Metallicity strongly correlates with the IRX-\beta scatter, this also results from the older stars and higher masses at higher beta values. Galaxies with higher metallicities show higher IRX and higher beta values. The correlation with specific dust mass strongly shifts the galaxies away from the IRX-\beta relation towards lower \b{eta} values. We find that more compact galaxies witness a larger amount of attenuation than less compact galaxies. There is a subtle variation in the dust attenuation scatter between edge-on and face-on galaxies, but the difference is not statistically significant. Galaxy environments do not significantly affect dust attenuation in our sample of star-forming galaxies at intermediate redshift., Comment: 14 pages, 13 figures, accepted for publication in A&A

Metallicity gradients refer to the sloped radial profile of metallicities of gas and stars and are commonly seen in disk galaxies. A well-defined metallicity gradient of the Galactic disk is observed particularly well with classical Cepheids, which are good stellar tracers thanks to their period-luminosity relation allowing precise distance estimation and other advantages. However, the measurement of the inner-disk gradient has been impeded by the incompleteness of previous samples of Cepheids and limitations of optical spectroscopy in observing highly reddened objects. Here we report the metallicities of 16 Cepheids measured with high-resolution spectra in the near-infrared YJ bands. These Cepheids are located at 3-5.6 kpc in the Galactocentric distance, R(GC), and reveal the metallicity gradient in this range for the first time. Their metallicities are mostly between 0.1 and 0.3 dex in [Fe/H] and more or less follow the extrapolation of the metallicity gradient found in the outer part, R(GC) larger than 6.5 kpc. The gradient in the inner disk may be shallower or even flat, but the small sample does not allow to determine the slope precisely. More extensive spectroscopic observations would also be necessary for studying minor populations, if any, with higher or lower metallicities that were reported in previous literature. In addition, three-dimensional velocities of our inner-disk Cepheids show the kinematic pattern that indicates non-circular orbits caused by the Galactic bar, which is consistent with the patterns reported in recent studies on high-mass star-forming regions and red giant branch stars., Comment: Accepted for publication in ApJ. 10 pages, 2 figures, and 2 tables

We present 850um imaging of the XMM-LSS field observed for 170 hours as part of the James Clerk Maxwell Telescope SCUBA-2 Large eXtragalactic Survey (S2LXS). S2LXS XMM-LSS maps an area of 9 square degrees, reaching a moderate depth of 1-sigma ~ 4 mJy/beam. This is the largest contiguous area of extragalactic sky mapped by JCMT at 850um to date. The wide area of the S2LXS XMM-LSS survey allows us to probe the ultra-bright (S_850um > 15 mJy), yet rare submillimetre population. We present the S2LXS XMM-LSS catalogue, which comprises 40 sources detected at >5-sigma significance, with deboosted flux densities in the range of 7 mJy to 48 mJy. We robustly measure the bright-end of the 850um number counts at flux densities >7 mJy, reducing the Poisson errors compared to existing measurements. The S2LXS XMM-LSS observed number counts show the characteristic upturn at bright fluxes, expected to be motivated by local sources of submillimetre emission and high-redshift strongly lensed galaxies. We find that the observed 850um number counts are best reproduced by model predictions that include either strong lensing or source blending from a 15 arcsec beam, indicating that both may make an important contribution to the observed over-abundance of bright single dish 850um selected sources. We make the S2LXS XMM-LSS 850um map and >5-sigma catalogue presented here publicly available., Comment: Accepted for publication in MNRAS

It has long been recognized that the key to unlocking the mystery of cuprate high-Tc superconductivity lies in understanding the anomalous normal state from which pairs form and condense. While many of its defining properties have been identified, they are often considered either at a singular doping level or as an isolated phenomenon as a function of doping. As a result, their relation to each other and to the pseudogap (PG), strange metal (SM) and non-superconducting (non-SC) regimes that define the cuprate phase diagram has yet to be elucidated. Here, we report a high-field in-plane MR study on several cuprate families spanning all 3 regimes that reveal a complex yet nonetheless systematic evolution of the form of the MR, with each regime possessing its own distinct scaling behavior. In the PG regime, the MR exhibits pure H/T^2 scaling at low fields and H-linearity at the highest field strengths. While the H-linearity persists inside the SM regime, the scaling changes abruptly to H/T. The size of the H-linear slope, meanwhile, is found to be correlated with both the T-linear resistivity coefficient and Tc, strengthening the characterization of the SM regime as a quantum critical phase. We interpret the omnipresence of H-linear MR across both regimes as a signature of highly anisotropic, possibly discontinuous features on the Fermi surface. Finally, within the non-SC, Fermi-liquid regime, we observe a recovery of conventional Kohler scaling. This comprehensive study establishes the distinct nature of the magnetotransport within each regime and identifies power-law scaling of the normal state MR as a defining feature of SC hole-doped cuprates. The incompatibility of such power-law scaling with any known variant of Boltzmann transport theory motivates the quest for an altogether new theoretical framework, one in which the MR is entirely decoupled from elastic impurity scattering.

The anomalous strange metal phase found in high-$T_c$ cuprates does not follow the conventional condensed-matter principles enshrined in the Fermi liquid and presents a great challenge for theory. Highly precise experimental determination of the electronic self-energy can provide a test bed for theoretical models of strange metals, and angle-resolved photoemission can provide this as a function of frequency, momentum, temperature and doping. Here we show that constant energy cuts through the nodal spectral function in (Pb,Bi)$_{2}$Sr$_{2-x}$La$_x$CuO$_{6+\delta}$ have a non-Lorentzian lineshape, meaning the nodal self-energy is $k$ dependent. We show that the experimental data are captured remarkably well by a power law with a $k$-dependent scaling exponent smoothly evolving with doping, a description that emerges naturally from AdS/CFT-based semi-holography. This puts a spotlight on holographic methods for the quantitative modelling of strongly interacting quantum materials like the cuprate strange metals.

We analyzed the evolution of 3GHz luminosity function of radio selected galaxies through cosmic time, up to about 1 Gyr after Big Bang, with making use of the VLA-COSMOS3GHz large project. We estimated the luminosity function for SFGs and AGNs in the VLA-COSMOS field respectively with two independent methods, the non-parametric C-method for accuracy to avoid the effect of cosmic variance and parametric MCMC method assuming pure luminosity evolution. We obtained pure luminosity evolution parameter as L*=(1+z)(3.36-0.31)z for SFG and L* = (1+z)(2.91-0.99)z for AGN. The resultant model agreed well with observed number counts down to sub-muJy level. Additionally, we compared the model with cosmic star formation rate density history with multiple observations in various wavelength and confirmed that our result is consistent with literature up to z=3. We further analyzed the statistical effect of gravitational lensing due to the dark matter halos and found that the effect is maximized at S_3GHz = 100muJy with about 1% contribution for SFG and less than 0.5% for AGN for the flux range considered in this study. In order to evaluate the effect of lensing magnification on parameter estimation in the SKA observations, we performed Fisher analysis and find that while the bias is limited, there is a distinguishable effect on SFG LF evolution parameter with SKA I MID wide survey, and all-sky and wide survey for AGN LF evolution parameters., Comment: 12 pages, 7 figures

Strange metals possess highly unconventional transport characteristics, such as a linear-in-temperature ($T$) resistivity, an inverse Hall angle that varies as $T^2$ and a linear-in-field ($H$) magnetoresistance. Identifying the origin of these collective anomalies has proved profoundly challenging, even in materials such as the hole-doped cuprates that possess a simple band structure. The prevailing dogma is that strange metallicity in the cuprates is tied to a quantum critical point at a doping $p*$ inside the superconducting dome. Here, we study the high-field in-plane magnetoresistance of two superconducting cuprate families at doping levels beyond $p*$. At all dopings, the magnetoresistance exhibits quadrature scaling and becomes linear at high $H/T$ ratios. Moreover, its magnitude is found to be much larger than predicted by conventional theory and insensitive to both impurity scattering and magnetic field orientation. These observations, coupled with analysis of the zero-field and Hall resistivities, suggest that despite having a single band, the cuprate strange metal phase hosts two charge sectors, one containing coherent quasiparticles, the other scale-invariant `Planckian' dissipators., Comment: 20 pages, 9 figures and 3 tables (including Supplementary Information)

The first generation of stars were born a few hundred million years after the big bang. These stars synthesized elements heavier than H and He, that are later expelled into the interstellar medium, initiating the rise of metals. Within this enriched medium, the first dust grains formed. This event is cosmological crucial for molecule formation as dust plays a major role by cooling low-metallicity star-forming clouds which can fragment to create lower mass stars. Collecting information on these first dust grains is difficult because of the negative alliance of large distances and low dust masses. We combine the observational information from galaxies at redshifts 5 < z < 10 to constrain their dust emission and theoretically understand the first evolutionary phases of the dust cycle. Spectral energy distributions (SEDs) are fitted with CIGALE and the physical parameters and their evolution are modelled. From this SED fitting, we build a dust emission template for this population of galaxies in the epoch of reionization. Our new models explain why some early galaxies are observed and others are not. We follow in time the formation of the first grains by supernovae later destroyed by other supernova blasts and expelled in the circumgalactic and intergalactic media. We have found evidence for the first dust grains formed in the universe. But, above all, this letter underlines the need to collect more data and to develop new facilities to further constrain the dust cycle in galaxies in the epoch of reionization., Comment: Paper accepted for publication in section 4. Extragalactic astronomy of Astronomy and Astrophysics (Feb. 2020). Correction typo in caption of Fig. 1

An important aspect of quenching star formation is the removal of the cold interstellar medium (ISM; non-ionised gas and dust) from a galaxy. In addition, dust grains can be destroyed in a hot or turbulent medium. The adopted timescale of dust removal usually relies on uncertain theoretical estimates. It is tricky to track the dust removal, because usually dust is constantly replenished by consecutive generations of stars. Our objective is to measure observationally the timescale of dust removal. We here explore an approach to select galaxies which do have detectable amounts of dust and cold ISM but exhibit a low current dust production rate. Any decrease of the dust and gas content as a function of the age of such galaxies therefore must be attributed to processes governing the ISM removal. We used a sample of galaxies detected by Herschel in the far-infrared with visually assigned early-type morphology or spirals with red colours. We also obtained JCMT/SCUBA-2 observations for five of them. We discovered an exponential decline of the dust-to-stellar mass ratio with age, which we interpret as an evolutionary trend of dust removal from these galaxies. For the first time we directly measure the dust removal timescale in such galaxies to be tau=(2.5+-0.4) Gyr (the corresponding half-life time is (1.75+-0.25) Gyr). This quantity may be used in models in which it must be assumed a priori and cannot be derived. Any process which removes dust in these galaxies, such as dust grain destruction, cannot happen on shorter timescales. The timescale is comparable to the quenching timescales found in simulations for galaxies with similar stellar masses. The dust is likely of internal, not external origin. It was either formed in the past directly by supernovae, or from seeds produced by SNe and with grain growth in the ISM contributing substantially to the dust mass accumulation., Comment: Astronomy & Astrophysics, accepted; 13 pages, 9 figures, 1 table

The Borexino detector measures solar neutrino fluxes via neutrino-electron elastic scattering. Observed spectra are determined by the solar-$\nu_{e}$ survival probability $P_{ee}(E)$, and the chiral couplings of the neutrino and electron. Some theories of physics beyond the Standard Model postulate the existence of Non-Standard Interactions (NSI's) which modify the chiral couplings and $P_{ee}(E)$. In this paper, we search for such NSI's, in particular, flavor-diagonal neutral current interactions that modify the $\nu_e e$ and $\nu_\tau e$ couplings using Borexino Phase II data. Standard Solar Model predictions of the solar neutrino fluxes for both high- and low-metallicity assumptions are considered. No indication of new physics is found at the level of sensitivity of the detector and constraints on the parameters of the NSI's are placed. In addition, with the same dataset the value of $\sin^2\theta_W$ is obtained with a precision comparable to that achieved in reactor antineutrino experiments., Comment: 28 pages, 7 figures. Slight modifications in the title, abstract, and conclusion. Few references added. Text expanded for clarity. Accepted in JHEP

We use the new release of the AKARI Far-Infrared all sky Survey matched with the NVSS radio database to investigate the local ($z<0.25$) far infrared-radio correlation (FIRC) of different types of extragalactic sources. To obtain the redshift information for the AKARI FIS sources we crossmatch the catalogue with the SDSS DR8. This also allows us to use emission line properties to divide sources into four categories: i) star-forming galaxies (SFGs), ii) composite galaxies (displaying both star-formation and active nucleus components), iii) Seyfert galaxies, and iv) low-ionization nuclear emission-line region (LINER) galaxies. We find that the Seyfert galaxies have the lowest FIR/radio flux ratios and display excess radio emission when compared to the SFGs. We conclude that FIRC can be used to separate SFGs and AGNs only for the most radio-loud objects., Comment: 9 pages, accepted to PASJ

In cuprates, the strong correlations in proximity to the antiferromagnetic Mott insulating state give rise to an array of unconventional phenomena beyond high temperature superconductivity. Developing a complete description of the ground state evolution is crucial to decoding the complex phase diagram. Here we use the structure of broken translational symmetry, namely $d$-form factor charge modulations in (Bi,Pb)$_2$(Sr,La)$_2$CuO$_{6+\delta}$, as a probe of the ground state reorganization that occurs at the transition from truncated Fermi arcs to a large Fermi surface. We use real space imaging of nanoscale electronic inhomogeneity as a tool to access a range of dopings within each sample, and we definitively validate the spectral gap $\Delta$ as a proxy for local hole doping. From the $\Delta$-dependence of the charge modulation wavevector, we discover a commensurate to incommensurate transition that is coincident with the Fermi surface transition from arcs to large hole pocket, demonstrating the qualitatively distinct nature of the electronic correlations governing the two sides of this quantum phase transition. Furthermore, the doping dependence of the incommensurate wavevector on the overdoped side is at odds with a simple Fermi surface driven instability., Comment: 10 pages, 4 figures

Deep MIR surveys have revealed numerous strongly star-forming galaxies at redshift z~<2. Their MIR fluxes are produced by a combination of continuum and PAH emission features. The PAH features can dominate the total MIR flux, but are difficult to measure without spectroscopy. We aim to study star-forming galaxies by using a blind spectroscopic survey at MIR wavelengths to understand evolution of their star formation rate (SFR) and specific SFR up to z~=0.5, by paying particular attention to their PAH properties. We conducted a low-resolution (R~=50) slitless spectroscopic survey at 5-13um of 9um flux-selected sources (>0.3 mJy) around the North Ecliptic Pole with the Infrared Camera (IRC) onboard AKARI. After removing 11 AGN candidates by using the IRC photometry, we identified 48 PAH galaxies with PAH 6.2, 7.7, and 8.6um features at z<0.5. The rest-frame optical-MIR spectral energy distributions (SEDs) based on CFHT and AKARI/IRC imaging covering 0.37-18um were produced, and analysed in conjunction with the PAH spectroscopy. We defined the PAH enhancement by using the luminosity ratio of the 7.7um PAH feature over the 3.5um stellar component of the SEDs. The rest-frame SEDs of all PAH galaxies have a universal shape with stellar and 7.7um bumps, except that the PAH enhancement significantly varies as a function of the PAH luminosities. We identified a PAH-enhanced population at z~>0.35, whose SEDs and luminosities are typical of luminous infrared galaxies. They show particularly larger PAH enhancement at high luminosity, implying that they are vigorous star-forming galaxies with elevated specific SFR. Our composite starburst model that combines a very young and optically very thick starburst with a very old population can successfully reproduce most of their SED characteristics, although we could not confirm this optically thick component from our spectral analysis., Comment: 61 pages, 24 figures, accepted for publication in Astronomy and Astrophysics

We grew 20-100 nm thick films of B20 FeGe by molecular beam epitaxy and investigated the surface structures via scanning tunneling microscopy. We observed the atomic resolution of each of the four possible chemical layers in FeGe(-1-1-1). An average hexagonal surface unit cell is observed via scanning tunneling microscopy, low energy electron diffraction, and reflection high energy electron diffraction resulting in a size of ~6.84 {\AA} in agreement with the bulk expectation. Furthermore, the atomic resolution and registry across triple-layer step edges definitively determine the grain orientation as (111) or (-1-1-1). Further verification of the grain orientation is made by Ar+ sputtering FeGe(-1-1-1) surface allowing direct imaging of the subsurface layer., Comment: 19 pages, 7 figures

Techniques to classify galaxies solely based on photometry will be necessary for future large cosmology missions, such as Euclid or LSST. However, the precision of classification is always lower in photometric surveys and can be systematically biased with respect to classifications based upon spectroscopic data. We verified how precisely the detailed classification scheme introduced by Siudek et al. (2018, hereafter: S1) for galaxies at z~0.7 could be reproduced if only photometric data are available. We applied the Fisher Expectation-Maximization (FEM) unsupervised clustering algorithm to 54,293 VIPERS galaxies working in a parameter space of reliable photometric redshifts and 12 corresponding rest-frame magnitudes. The FEM algorithm distinguishes four main groups: (1) red, (2) green, (3) blue, and (4) outliers. Each group is further divided into 3, 3, 4, and 2 subclasses, respectively. The accuracy of reproducing galaxy classes using spectroscopic data is high: 92%, 84%, 96% for red, green, and blue classes, respectively, except for dusty star-forming galaxies. The presented verification of the photometric classification demonstrates that large photometric samples can be used to distinguish different galaxy classes at z > 0.5 with an accuracy provided so far only by spectroscopic data except for particular galaxy classes., Comment: the letter submitted to MNRAS, 6 pages, 4 figures. Please contact Malgorzata Siudek (msiudek@ifae.es) if you are interested in the catalogue

Various galaxy classification schemes have been developed so far to constrain the main physical processes regulating evolution of different galaxy types. In the era of a deluge of astrophysical information and recent progress in machine learning, a new approach to galaxy classification becomes imperative. We employ a Fisher Expectation-Maximization unsupervised algorithm working in a parameter space of 12 rest-frame magnitudes and spectroscopic redshift. The model (DBk) and the number of classes (12) were established based on the joint analysis of standard statistical criteria and confirmed by the analysis of the galaxy distribution with respect to a number of classes and their properties. This new approach allows us to classify galaxies based just on their redshifts and UV-NIR spectral energy distributions. The FEM unsupervised algorithm has automatically distinguished 12 classes: 11 classes of VIPERS galaxies and an additional class of broad-line AGNs. After a first broad division into blue, green and red categories we obtained a further sub-division into three red, three green, and five blue galaxy classes. The FEM classes follow the galaxy sequence from the earliest to the latest types that is reflected in their colours (which are constructed from rest-frame magnitudes used in classification procedure) but also their morphological, physical, and spectroscopic properties (not included in the classification scheme). We demonstrate that the members of each class share similar physical and spectral properties. In particular, we are able to find three different classes of red passive galaxy populations. Thus, we demonstrate the potential of an unsupervised approach to galaxy classification and we retrieve the complexity of galaxy populations at z~0.7, a task that usual simpler colour-based approaches cannot fulfil., Comment: published in A&A, 27 pages, 10 figures, 4 appendixes. Please contact Malgorzata Siudek (msiudek@ifae.es) if you are interested in the catalogue

We present the dust mass function (DMF) of 15,750 galaxies with redshift $z< 0.1$, drawn from the overlapping area of the GAMA and {\it H-}ATLAS surveys. The DMF is derived using the density corrected $V_{\rm max}$ method, where we estimate $V_{\rm max}$ using: (i) the normal photometric selection limit ($pV_{\rm max}$) and (ii) a bivariate brightness distribution (BBD) technique, which accounts for two selection effects. We fit the data with a Schechter function, and find $M^{*}=(4.65\pm0.18)\times 10^{7}\,h^2_{70}\, M_{\odot}$, $\alpha=(1.22\pm 0.01)$, $\phi^{*}=(6.26\pm 0.28)\times 10^{-3}\,h^3_{70}\,\rm Mpc^{-3}\,dex^{-1}$. The resulting dust mass density parameter integrated down to $10^4\,M_{\odot}$ is $\Omega_{\rm d}=(1.11 \pm0.02)\times 10^{-6}$ which implies the mass fraction of baryons in dust is $f_{m_b}=(2.40\pm0.04)\times 10^{-5}$; cosmic variance adds an extra 7-17\,per\,cent uncertainty to the quoted statistical errors. Our measurements have fewer galaxies with high dust mass than predicted by semi-analytic models. This is because the models include too much dust in high stellar mass galaxies. Conversely, our measurements find more galaxies with high dust mass than predicted by hydrodynamical cosmological simulations. This is likely to be from the long timescales for grain growth assumed in the models. We calculate DMFs split by galaxy type and find dust mass densities of $\Omega_{\rm d}=(0.88\pm0.03)\times 10^{-6}$ and $\Omega_{\rm d}=(0.060\pm0.005)\times 10^{-6}$ for late-types and early-types respectively. Comparing to the equivalent galaxy stellar mass functions (GSMF) we find that the DMF for late-types is well matched by the GMSF scaled by $(8.07\pm0.35) \times 10^{-4}$., Comment: 25 Pages, 18 Figures. Submitted December 2017

We study the electronic structure of Tsai-type cluster-based quasicrystalline approximants, Au$_{64}$Ge$_{22}$Yb$_{14}$ (AGY-I), Au$_{63.5}$Ge$_{20.5}$Yb$_{16}$ (AGY-II), and Zn$_{85.4}$Yb$_{14.6}$ (Zn-Yb), by means of photoemission spectroscopy. In the valence band hard x-ray photoemission spectra of AGY-II and Zn-Yb, we separately observe a fully occupied Yb 4$f$ state and a valence fluctuation derived Kondo resonance peak, reflecting two inequivalent Yb sites, a single Yb atom in the cluster center and its surrounding Yb icosahedron, respectively. The fully occupied 4$f$ signal is absent in AGY-I containing no Yb atom in the cluster center. The results provide direct evidence for a heterogeneous valence state in AGY-II and Zn-Yb.

The recent updates of the North Ecliptic Pole deep (0.5~deg$^2$, NEP-Deep) multi-wavelength survey covering from X-ray to radio-wave is presented. The NEP-Deep provides us with several thousands of 15~$\mu$m or 18~$\mu$m selected sample of galaxies, which is the largest sample ever made at this wavelengths. A continuous filter coverage in the mid-infrared wavelength (7, 9, 11, 15, 18, and 24~$\mu$m) is unique and vital to diagnose the contributions from starbursts and AGNs in the galaxies out to $z$=2.The new goal of the project is to resolve the nature of the cosmic star formation history at the violent epoch (e.g. $z$=1--2), and to find a clue to understand its decline from $z$=1 to present universe by utilizing the unique power of the multi-wavelength survey. The progress in this context is briefly mentioned., Comment: 4 pages, 2 figures, AKARI conference proceedings; accepted to PKAS

We built a 8um selected sample of galaxies in the NEP-AKARI field by defining 4 redshift bins with the four AKARI bands at 11, 15, 18 and 24 microns (0.15

We report the identification of four millimeter line emitting galaxies with the Atacama Large Milli/submillimeter Array (ALMA) in SSA22 Field (ADF22). We analyze the ALMA 1.1 mm survey data, with an effective survey area of 5 arcmin$^2$, a frequency range of 253.1--256.8 and 269.1--272.8 GHz, angular resolution of 0".7 and RMS noise of 0.8 mJy beam$^{-1}$ at 36 km s$^{-1}$ velocity resolution. We detect four line emitter candidates with significance levels above $6 \sigma$. We identify one of the four sources as a CO(9-8) emitter at $z = 3.1$ in a member of the proto-cluster known in this field. Another line emitter with an optical counterpart is likely a CO(4-3) emitter at $z = 0.7$. The other two sources without any millimeter continuum or optical/near-infrared counterpart are likely to be [CII] emitter candidates at $z = 6.0$ and $6.5$. The equivalent widths of the [CII] candidates are consistent with those of confirmed high-redshift [CII] emitters and candidates, and are a factor of 10 times larger than that of the CO(9-8) emitter detected in this search. The [CII] luminosity of the candidates are $4-7 \times 10^8~\rm L_\odot$. The star formation rates (SFRs) of these sources are estimated to be $10-20~\rm M_{\odot}~yr^{-1}$ if we adopt an empirical [CII] luminosity - SFR relation. One of them has a relatively low-S/N ratio, but shows features characteristic of emission lines. Assuming that at least one of the two candidates is a [CII] emitter, we derive a lower limit of [CII]-based star formation rate density (SFRD) at $z~\sim~6$. The resulting value of $> 10^{-2}$ $\rm M_\odot yr^{-1} Mpc^{-3}$ is consistent with the dust-uncorrected UV-based SFRD. Future millimeter/submillimeter surveys can be used to detect a number of high redshift line emitters, with which to study the star formation history in the early Universe., Comment: 14 pages, 10 figures. Accepted to PASJ

The aim of this work is to characterize physical properties of Ultra Luminous Infrared Galaxies (ULIRGs) and Luminous Infrared Galaxies (LIRGs) detected in the far-infrared (FIR) 90um band in the AKARI Deep Field-South (ADF-S) survey. In particular, we want to estimate the AGN contribution to the [U]LIRGs' infrared emission and which types of AGNs are related to their activity. We examined 69 galaxies at z>0.05 detected at 90um by the AKARI satellite in the ADF-S, with optical counterparts and spectral coverage from the ultraviolet to the FIR. We used two independent spectral energy distribution fitting codes: one fitting the SED from FIR to FUV (CIGALE) and gray-body + power spectrum fit for the infrared part of the spectra (CMCIRSED) in order to identify a subsample of [U]LIRGs, and to estimate their properties. Based on the CIGALE SED fitting, we have found that [U]LIRGs selected at the 90um AKARI band compose ~56% of our sample (we found 17 ULIRGs and 22 LIRGs, spanning over the redshift range 0.06

We aim to use the a new and improved version of AKARI all sky survey catalogue of far-infrared sources to recalibrate the formula to derive the total infrared luminosity. We cross-match the faint source catalogue (FSC) of IRAS with the new AKARI-FIS and obtained a sample of 2430 objects. Then we calculate the total infrared (TIR) luminosity $L_{\textrm{TIR}}$ from the Sanders at al. (1996) formula and compare it with total infrared luminosity from AKARI FIS bands to obtain new coefficients for the general relation to convert FIR luminosity from AKARI bands to the TIR luminosity., Comment: 4 pages, 4 figures

We study low energy excitations in the quantum breathing pyrochlore antiferromagnet Ba$_3$Yb$_2$Zn$_5$O$_{11}$ by combination of inelastic neutron scattering (INS) and thermodynamical properties measurements. The INS spectra are quantitatively explained by spin-1/2 single-tetrahedron model having $XXZ$ anisotropy and Dzyaloshinskii-Moriya interaction. This model has a two-fold degeneracy of the lowest-energy state per tetrahedron and well reproduces the magnetization curve at 0.5 K and heat capacity above 1.5 K. At lower temperatures, however, we observe a broad maximum in the heat capacity around 63 mK, demonstrating that a unique quantum ground state is selected due to extra perturbations with energy scale smaller than the instrumental resolution of INS., Comment: 5 pages 3 figures, Phys. Rev. B rapid communication in press

We explore the evolution of the statistical distribution of galaxy morphological properties and colours over the redshift range $0.5

We trace the evolution and the star formation history of passive galaxies, using a subset of the VIMOS Public Extragalactic Redshift Survey (VIPERS). We extracted from the VIPERS survey a sample of passive galaxies in the redshift range 0.4

We present the Spitzer-IRAC/MIPS Extragalactic survey (SIMES) in the South Ecliptic Pole (SEP) field. The large area covered (7.7 deg$^2$), together with one of the lowest Galactic cirrus emissions in the entire sky and a very extensive coverage by Spitzer, Herschel, Akari, and GALEX, make the SIMES field ideal for extragalactic studies. The elongated geometry of the SIMES area ($\approx$4:1), allowing for a significant cosmic variance reduction, further improves the quality of statistical studies in this field. Here we present the reduction and photometric measurements of the Spitzer/IRAC data. The survey reaches a depth of 1.93 and 1.75 $\mu$Jy (1$\sigma$) at 3.6 and 4.5 $\mu$m, respectively. We discuss the multiwavelength IRAC--based catalog, completed with optical, mid-- and far--IR observations. We detect 341,000 sources with F$_{3.6\mu m} \geq 3\sigma$. Of these, 10% have an associated 24 $\mu$m counterpart, while 2.7% have an associated SPIRE source. We release the catalog through the NASA/IPAC Infrared Science Archive (IRSA). Two scientific applications of these IRAC data are presented in this paper: first we compute integral number counts at 3.6 $\mu$m. Second, we use the [3.6]--[4.5] color index to identify galaxy clusters at z$>$1.3. We select 27 clusters in the full area, a result consistent with previous studies at similar depth.

We present a method of selection of 24~$\mu$m galaxies from the AKARI North Ecliptic Pole (NEP) Deep Field down to $150 \mbox{ }\mu$Jy and measurements of their two-point correlation function. We aim to associate various 24 $\mu$m selected galaxy populations with present day galaxies and to investigate the impact of their environment on the direction of their subsequent evolution. We discuss using of Support Vector Machines (SVM) algorithm applied to infrared photometric data to perform star-galaxy separation, in which we achieve an accuracy higher than 80\%. The photometric redshift information, obtained through the CIGALE code, is used to explore the redshift dependence of the correlation function parameter ($r_{0}$) as well as the linear bias evolution. This parameter relates galaxy distribution to the one of the underlying dark matter. We connect the investigated sources to their potential local descendants through a simplified model of the clustering evolution without interactions. We observe two different populations of star-forming galaxies, at $z_{med}\sim 0.25$, $z_{med}\sim 0.9$. Measurements of total infrared luminosities ($L_{TIR}$) show that the sample at $z_{med}\sim 0.25$ is composed mostly of local star-forming galaxies, while the sample at $z_{med}\sim0.9$ is composed of luminous infrared galaxies (LIRGs) with $L_{TIR}\sim 10^{11.62}L_{\odot}$. We find that dark halo mass is not necessarily correlated with the $L_{TIR}$: for subsamples with $L_{TIR}= 10^{11.15} L_{\odot}$ at $z_{med}\sim 0.7$ we observe a higher clustering length ($r_{0}=6.21\pm0.78$ $[h^{-1} \mbox{Mpc}]$) than for a subsample with mean $L_{TIR}=10^{11.84} L_{\odot}$ at $z_{med}\sim1.1$ ($r_{0}=5.86\pm0.69$ $h^{-1} \mbox{Mpc}$). We find that galaxies at $z_{med}\sim 0.9$ can be ancestors of present day $L_{*}$ early type galaxies, which exhibit a very high $r_{0}\sim 8$~$h^{-1} \mbox{Mpc}$., Comment: 13 pages, 8 figures

Concerted effort is currently ongoing to open up the Epoch of Reionization (EoR) ($z\sim$15-6) for studies with IR and radio telescopes. Whereas IR detections have been made of sources (Lyman-$\alpha$ emitters, quasars and drop-outs) in this redshift regime in relatively small fields of view, no direct detection of neutral hydrogen, via the redshifted 21-cm line, has yet been established. Such a direct detection is expected in the coming years, with ongoing surveys, and could open up the entire universe from $z\sim$6-200 for astrophysical and cosmological studies, opening not only the EoR, but also its preceding Cosmic Dawn ($z\sim$30-15) and possibly even the later phases of the Dark Ages ($z\sim$200-30). All currently ongoing experiments attempt statistical detections of the 21-cm signal during the EoR, with limited signal-to-noise. Direct imaging, except maybe on the largest (degree) scales at lower redshifts, as well as higher redshifts will remain out of reach. The Square Kilometre Array(SKA) will revolutionize the field, allowing direct imaging of neutral hydrogen from scales of arc-minutes to degrees over most of the redshift range $z\sim$6-28 with SKA1-LOW, and possibly even higher redshifts with the SKA2-LOW. In this SKA will be unique, and in parallel provide enormous potential of synergy with other upcoming facilities (e.g. JWST). In this chapter we summarize the physics of 21-cm emission, the different phases the universe is thought to go through, and the observables that the SKA can probe, referring where needed to detailed chapters in this volume (Abridged)., Comment: Accepted for publication in the SKA Science Book 'Advancing Astrophysics with the Square Kilometre Array', to appear in 2015. PoS(AASKA14)001

Galaxies' rest-frame ultraviolet (UV) properties are often used to directly infer the degree to which dust obscuration affects the measurement of star formation rates. While much recent work has focused on calibrating dust attenuation in galaxies selected at rest-frame ultraviolet wavelengths, locally and at high-$z$, here we investigate attenuation in dusty, star-forming galaxies (DSFGs) selected at far-infrared wavelengths. By combining multiwavelength coverage across 0.15--500\,$\mu$m in the COSMOS field, in particular making use of {\it Herschel} imaging, and a rich dataset on local galaxies, we find a empirical variation in the relationship between rest-frame UV slope ($\beta$) and ratio of infrared-to-ultraviolet emission ($L_{\rm IR}/L_{\rm UV}\equiv\,IRX$) as a function of infrared luminosity, or total star formation rate, SFR. Both locally and at high-$z$, galaxies above SFR$\gt$50\,M$_\odot$\,yr$^{-1}$ deviate from the nominal $IRX-\beta$ relation towards bluer colors by a factor proportional to their increasing IR luminosity. We also estimate contamination rates of DSFGs on high-$z$ dropout searches of $\ll1$\%\ at $z\lt4-10$, providing independent verification that contamination from very dusty foreground galaxies is low in LBG searches. Overall, our results are consistent with the physical interpretation that DSFGs, e.g. galaxies with $>50$\,M$_\odot$\,yr$^{-1}$, are dominated at all epochs by short-lived, extreme burst events, producing many young O and B stars that are primarily, yet not entirely, enshrouded in thick dust cocoons. The blue rest-frame UV slopes of DSFGs are inconsistent with the suggestion that most DSFGs at $z\sim2$ exhibit steady-state star formation in secular disks., Comment: 16 pages, 8 figures, accepted for publication in ApJ

The effect of magnetic field on the static and dynamic spin correlations in the non-centrosymmetric heavy-fermion superconductor CePt$_3$Si was investigated by neutron scattering. The application of a magnetic field B increases the antiferromagnetic (AFM) peak intensity. This increase depends strongly on the field direction: for B${\parallel}$[0 0 1] the intensity increases by a factor of 4.6 at a field of 6.6 T, which corresponds to more than a doubling of the AFM moment, while the moment increases by only 10 % for B${\parallel}$[1 0 0] at 5 T. This is in strong contrast to the inelastic response near the antiferromagnetic ordering vector, where no marked field variations are observed for B${\parallel}$[0 0 1] up to 3.8 T. The results reveal that the AFM state in CePt$_3$Si, which coexists with superconductivity, is distinctly different from other unconventional superconductors., Comment: 5 pages, 4 figures, accepted for publication in Phys. Rev. B

This paper analyses the behaviour of the gas-to-dust mass ratio (G/D) of local Universe galaxies over a large metallicity range. We combine three samples: the Dwarf Galaxy Survey, the KINGFISH survey and a subsample from Galametz et al. (2011) totalling 126 galaxies, covering a 2 dex metallicity range, with 30% of the sample with 12+log(O/H) < 8.0. The dust masses are homogeneously determined with a semi-empirical dust model, including submm constraints. The atomic and molecular gas masses are compiled from the literature. Two XCO are used to estimate molecular gas masses: the Galactic XCO, and a XCO depending on the metallicity (as Z^{-2}). Correlations with morphological types, stellar masses, star formation rates and specific star formation rates are discussed. The trend between G/D and metallicity is empirically modelled using power-laws (slope of -1 and free) and a broken power-law. We compare the evolution of the G/D with predictions from chemical evolution models. We find that out of the five tested galactic parameters, metallicity is the galactic property driving the observed G/D. The G/D versus metallicity relation cannot be represented by a power-law with a slope of -1 over the whole metallicity range. The observed trend is steeper for metallicities lower than ~ 8.0. A large scatter is observed in the G/D for a given metallicity, with a dispersion of 0.37 dex in metallicity bins of ~0.1 dex. The broken power-law reproduces best the observed G/D and provides estimates of the G/D that are accurate to a factor of 1.6. The good agreement of the G/D and its scatter with the three tested chemical evolution models shows that the scatter is intrinsic to galactic properties, reflecting the different star formation histories, dust destruction efficiencies, dust grain size distributions and chemical compositions across the sample. (abriged), Comment: 23 pages, 12 figures, accepted in Astronomy & Astrophysics

The main aim of this work is the characterization of physical properties of galaxies detected in the far infrared (FIR) in the AKARI Deep Field-South (ADF-S) survey. Starting from a catalog of the 1 000 brightest ADF-S sources in the WIDE-S (90$\mu$m) AKARI band, we constructed a subsample of galaxies with spectral coverage from the ultraviolet to the far infrared. We then analyzed the multiwavelength properties of this 90$\mu$m selected sample of galaxies. For galaxies without known spectroscopic redshifts we computed photometric redshifts using the codes Photometric Analysis for Redshift Estimate (Le PHARE) and Code Investigating GALaxy Emission (CIGALE), tested these photometric redshifts using spectroscopic redshifts, and compared the performances of both codes. To test the reliability of parameters obtained by fitting spectral energy distributions, a mock cataloge was generated. We built a large multiwavelength catalog of more than 500 ADF-S galaxies. We successfully fitted Spectral Energy Distributions of 186 galaxies with $\rm{\chi^2_{min}<4}$, and analyzed the output parameters of the fits. We conclude that our sample consists mostly of nearby actively star-forming galaxies, and all our galaxies have a relatively high metallicity. We estimated photometric redshifts for 113 galaxies from the whole ADF-S sample. Comparing the performance of Le PHARE and CIGALE, we found that CIGALE gives more reliable redshift estimates for our galaxies, which implies that including the IR photometry allows for substantial improvement of photometric redshift estimation., Comment: 16 pages, 20 figures, accepted for publication in A&A

We present the results of the analysis of multiwavelength Spectral Energy Distributions (SEDs) of far-infrared galaxies detected in the AKARI Deep Field-South (ADF--S) Survey. The analysis uses a carefully selected sample of 186 sources detected at the 90 $\mu$m AKARI band, identified as galaxies with cross-identification in public catalogues. For sources without known spectroscopic redshifts, we estimate photometric redshifts after a test of two independent methods: one based on using mainly the optical -- mid infrared range, and one based on the whole range of ultraviolet -- far infrared data. We observe a vast improvement in the estimation of photometric redshifts when far infrared data are included, compared with an approach based mainly on the optical -- mid infrared range. We discuss the physical properties of our far-infrared-selected sample. We conclude that this sample consists mostly of rich in dust and young stars nearby galaxies, and, furthermore, that almost 25% of these sources are (Ultra)Luminous Infrared Galaxies. Average SEDs normalized at 90 $\mu$m for normal galaxies (138 sources), LIRGs (30 sources), and ULIRGs (18 galaxies) a the significant shift in the peak wavelength of the dust emission, and an increasing ratio between their bolometric and dust luminosities which varies from 0.39 to 0.73., Comment: 8 pages, 7 figures, published in Earth, Planets and Space

The evolution of galaxies and the history of star formation in the Universe are among the most important topics in today's astrophysics. Especially, the role of small, irregular galaxies in the star-formation history of the Universe is not yet clear. Using the data from the AKARI IRC survey of the Large Magellanic Cloud at 3.2, 7, 11, 15, and 24 {\mu}m wavelengths, i.e., at the mid- and near-infrared, we have constructed a multiwavelength catalog containing data from a cross-correlation with a number of other databases at different wavelengths. We present the separation of different classes of stars in the LMC in color-color, and color-magnitude, diagrams, and analyze their contribution to the total LMC flux, related to point sources at different infrared wavelengths.

The unclear relationship between cuprate superconductivity and the pseudogap state remains an impediment to understanding the high transition temperature (Tc) superconducting mechanism. Here we employ magnetic-field-dependent scanning tunneling microscopy to provide phase-sensitive proof that d-wave superconductivity coexists with the pseudogap on the antinodal Fermi surface of an overdoped cuprate. Furthermore, by tracking the hole doping (p) dependence of the quasiparticle interference pattern within a single Bi-based cuprate family, we observe a Fermi surface reconstruction slightly below optimal doping, indicating a zero-field quantum phase transition in notable proximity to the maximum superconducting Tc. Surprisingly, this major reorganization of the system's underlying electronic structure has no effect on the smoothly evolving pseudogap., Comment: For higher-resolution figures, please see the published version

Merger processes play an important role in galaxy formation and evolution. To study the influence of merger processes on the evolution of dust properties and cosmic star formation rate, we investigate a local sample of major merger galaxies and a control sample of isolated galaxies using GALEX ultraviolet (UV) and Spitzer infrared (IR) images. Through a statistical study, we find that dust attenuation in merger galaxies is enhanced with respect to isolated galaxies. We find this enhancement is contributed mainly by spiral galaxies in spiral-spiral (S-S) pairs, and increases with the increasing stellar mass of a galaxy. Combining the IR and UV parts of star formation rates (SFRs), we then calculated the total SFRs and specific star formation rates (SSFRs). We find the SSFRs to be enhanced in merger galaxies. This enhancement depends on galaxy stellar mass and the companion's morphology, but depends little on whether the galaxy is a primary or secondary component or on the separation between two components. These results are consistent with a previous study based only on IR images. In addition, we investigate the nuclear contributions to SFRs. SFRs in paired galaxies are more concentrated in the central part of the galaxies than in isolate galaxies. Our studies of dust attenuation show that the nuclear parts of pairs most resemble ULIRGs. Including UV data in the present work not only provides reliable information on dust attenuation, but also refines analyses of SFRs., Comment: 21 pages, 21 figures

We present the first measurement of the angular two-point correlation function for AKARI 90-$\mu$m point sources, detected outside of the Milky Way plane and other regions characterized by high Galactic extinction, and categorized as extragalactic sources according to our far-infrared-color based criterion (Pollo et al. 2010). This is the first measurement of the large-scale angular clustering of galaxies selected in the far-infrared after IRAS measurements. Although a full description of clustering properties of these galaxies will be obtained by more detailed studies, using either spatial correlation function, or better information about properties and at least photometric redshifts of these galaxies, the angular correlation function remains the first diagnostics to establish the clustering properties of the catalog and observed galaxy population. We find a non-zero clustering signal in both hemispheres extending up to $\sim 40$ degrees, without any significant fluctuations at larger scales. The observed correlation function is well fitted by a power law function. The notable differences between a northern and southern hemisphere are found, which can be probably attributed to the photometry problems and point out to a necessity of performing a better calibration in the data from southern hemisphere., Comment: 6 pages, 6 figures, accepted for publication in Earth, Planets, and Space

An accurate estimation of the star formation-related properties of galaxies is crucial for understanding the evolution of galaxies. In galaxies, ultraviolet (UV) light emitted by recently formed massive stars is attenuated by dust, which is also produced by star formation (SF) activity, and is reemitted at mid- and far- infrared (IR) wavelengths. In this study, we investigate the star formation rate (SFR) and dust extinction using UV and IR data. We selected local galaxies which are detected at AKARI FIS 90 um and matched the IRAS IIFSCz 60 um select catalog. We measured FUV and NUV flux densities from GALEX images. We examined the SF and extinction of Local galaxies using four bands of AKARI. Then, we calculated FUV and total IR luminosities, and obtained the SF luminosity, L_{SF}, the total luminosity related to star formation activity, and the SFR. We find that in most galaxies, L_{SF} is dominated by L_{dust}. We also find that galaxies with higher SF activity have a higher fraction of their SF hidden by dust. In fact, the SF of galaxies with SFRs >20 M_{sun}/yr is almost completely hidden by dust. Our results boast a significantly higher precision with respect to previously published works, due to the use of much larger object samples from the AKARI and GALEX all sky surveys., Comment: 9 pages, 12 figures, accepted for publication in Earth, Planets, and Space, A few minor corrections, and a reference added