Mass Diagram Research Articles

Formation of millisecond pulsars with wide orbits

ABSTRACT Millisecond pulsars (MSPs) are a kind of radio pulsars with short spin periods, playing a key role in many aspects of stellar astrophysics. In recent years, some more MSPs with wide orbits ($\gt 30\, \rm d$) have been discovered, but their origin is still highly unclear. In this work, according to an adiabatic power-law assumption for the mass-transfer process, we carried out a large number of complete binary evolution computations for the formation of MSPs with wide orbits through the iron core-collapse supernova (CCSN) channel, in which a neutron star originating from a CCSN accretes matter from a red-giant star and spun up to millisecond periods. We found that this channel can form the observed MSPs with wide orbits in the range of $30\!-\!1200\, {\rm d}$, in which the white dwarf (WD) companions have masses in the range of $0.28\!-\!0.55\, \rm M_{\odot }$. We also found that almost all the observed MSPs can be reproduced by this channel in the WD companion mass versus orbital period diagram. We estimate that the Galactic numbers of the resulting MSPs from the CCSN channel are in the range of $\sim 4.8\!-\!8.5\times 10^{5}$. Compared with the accretion-induced collapse channel, the CCSN channel provides a main way to produce MSPs with wide orbits.

The miniJPAS survey: Evolution of luminosity and stellar mass functions of galaxies up to z~0.7

We aim to develop a robust methodology for constraining the luminosity and stellar mass functions (LMFs) of galaxies by solely using photometric measurements from multi-filter imaging surveys. We test the potential of these techniques for determining the evolution of these functions up to $z 0.7$ in the Javalambre Physics of the Accelerating Universe Astrophysical Survey (J-PAS), which will image thousands of square degrees in the northern hemisphere with an unprecedented photometric system that includes $54$ narrow band filters. As J-PAS is still an ongoing survey, we used the miniJPAS dataset (a stripe of $1$ deg$^2$ dictated according to the J-PAS strategy) for determining the LMFs of galaxies at $0.05 z 0.7$. Stellar mass and $B$-band luminosity for each of the miniJPAS galaxies are constrained using an updated version of our fitting code for spectral energy distribution, MUlti-Filter FITting (MUFFIT), whose values are based on non-parametric composite stellar population models and the probability distribution functions of the miniJPAS photometric redshifts. Galaxies are classified according to their star formation activity through the stellar mass versus rest-frame colour diagram corrected for extinction (MCDE) and we assign a probability to each source of being a quiescent or star-forming galaxy. Different stellar mass and luminosity completeness limits are set and parametrised as a function of redshift, for setting the limitations of our flux-limited sample ($r_ SDSS 22$) for the determination of the miniJPAS LMFs. The miniJPAS LMFs are parametrised according to Schechter-like functions via a novel maximum likelihood method accounting for uncertainties, degeneracies, probabilities, completeness, and priors. Overall, our results point to a smooth evolution with redshift ($0.05 z 0.7$) of the miniJPAS LMFs, which is in agreement with previous studies. The LMF evolution of star-forming galaxies mainly involve the bright and massive ends of these functions, whereas the LMFs of quiescent galaxies also exhibit a non-negligible evolution in their faint and less massive ends. The cosmic evolution of the global $B$-band luminosity density decreases by $ 0.1$ dex from $z=0.7$ to $0.05$; whereas for quiescent galaxies, this quantity roughly remains constant. In contrast, the stellar mass density increases by $ dex in the same redshift range, where the evolution is mainly driven by quiescent galaxies, owing to an overall increase in the number of this type of galaxy. In turn, this covers the majority and most massive galaxies, namely, $60$--$100$<!PCT!> of galaxies at $ (M_

Simultaneous Photometric and Spectroscopic Analysis of V505 Lacertae, a Photospherically and Chromospherically Active Contact Binary Star

New BVR photometric and high-resolution spectroscopic observations of V505 Lac are presented with Transiting Exoplanet Survey Satellite (TESS) photometric data. The orbital period has experienced a secular decrease during the past 16 yr. A clear anticorrelation in the primary and secondary eclipse timing variation (PSETV) obtained from the TESS data is also identified. A double-lined radial velocity (RV) curve is secured, and the effective temperatures of the less- and more-massive stars (Stars 1 and 2, respectively) are measured. Using a spectral subtraction technique, excess emissions are detected in the time-series Ca ii H and K and Hα lines for Star 2. Simultaneous analysis of the light and RV curves using the Wilson–Devinney (WD) code reveals that V505 Lac is a photospherically and chromospherically active W-subtype contact binary system. The component-star masses and radii are determined to an accuracy of approximately 1%. The WD spot model is individually applied to 221 light curves segmented from the TESS data so as to derive the spot parameters of a cool spot on Star 2. The combined variations in both longitude and colatitude among the spot parameters appear to be strongly associated with those of both the anticorrelation in the PSETV and the O’Connell effect in the TESS light curves. Robust negative linear relationships between the PSETV anticorrelation size and the O’Connell effect magnitude are found for the first time. Mass–radius, mass–luminosity, and mass ratio–mass diagrams of contact binaries, along with the mass ratio frequency distribution, are presented in an attempt to elucidate the evolutionary characteristics of these systems.

Repainting the colour–mass diagrams by unearthing the green mountain: dust-rich S0 galaxies in the colour–(galaxy stellar mass) diagram, and the colour–(black hole mass) relations for dust-poor versus dust-rich galaxies

ABSTRACT Lenticular galaxies are notoriously misclassified as elliptical galaxies and, as such, a (disc inclination)-dependent correction for dust is often not applied to the magnitudes of dusty lenticular galaxies. This results in overly red galaxy colours, impacting their distribution in the colour–magnitude diagram. It is revealed how this has led to an underpopulation of the ‘green valley’ by hiding a ‘green mountain’ of massive dust-rich lenticular galaxies – known to be built from gas-rich major mergers – within the ‘red sequence’ of colour–(stellar mass) diagrams. Correcting for dust, a ‘green mountain’ appears at M*,gal ∼ 1011 M⊙, along with signs of an extension to lower masses producing a ‘green range’ or ‘green ridge’ on the green side of the ‘red sequence’ and ‘blue cloud.’ The ‘red sequence’ is shown to be comprised of two components: a red plateau defined by elliptical galaxies with a near-constant colour and by lower-mass dust-poor lenticular galaxies, which are mostly a primordial population but may include faded/transformed spiral galaxies. The presence of the quasi-triangular-shaped galaxy evolution sequence, previously called the ‘Triangal’, is revealed in the galaxy colour–(stellar mass) diagram. It tracks the speciation of galaxies and their associated migration through the diagram. The connection of the ‘Triangal’ to previous galaxy morphology sequences (Fork, Trident, and Comb) is also shown herein. Finally, the colour–(black hole mass) diagram is revisited, revealing how the dust correction generates a blue–green sequence for the spiral and dust-rich lenticular galaxies that is offset from a green–red sequence defined by the dust-poor lenticular and elliptical galaxies.

Electron-capture supernovae in NS + He star systems and the double neutron star systems

ABSTRACT Electron-capture-supernovae (EC-SNe) provide an alternative channel for producing neutron stars (NSs). They play an important role in the formation of double NS (DNS) systems and the chemical evolution of galaxies, and contribute to the NS mass distribution in observations. It is generally believed that EC-SNe originate from e-captures on $\rm ^{24}Mg$ and $\rm ^{20}Ne$ in the massive degenerate oxygen–neon (ONe) cores with masses close to the Chandrasekhar limit (MCh). However, the origin of EC-SNe is still uncertain. In this paper, we systematically studied the EC-SNe in NS + He star systems by considering the explosive oxygen burning that may occur in the near-MCh ONe core. We provided the initial parameter spaces for producing EC-SNe in the initial orbital period − initial He star mass (log$P_{\rm orb}^{\rm i}-M_{\rm He}^{\rm i}$) diagram, and found that both $M_{\rm He}^{\rm i}$ and minimum $P_{\rm orb}^{\rm i}$ for EC-SNe increase with metallicity. Then, by considering NS kicks added to the newborn NS, we investigated the properties of the formed DNS systems after the He star companions collapse into NSs, such as the orbital periods, eccentricities, and spin periods of recycle pulsars (Pspin), etc. The results show that most of the observed DNS systems can be produced by NS kicks of $\lesssim$50 km s−1. In addition, we found that NSs could accrete more material if the residual H envelope on the He star companions is considered, which can form the mildly recycled pulsars (Pspin ∼ 20 ms) in DNS systems.

Massive red spiral galaxies in SDSS-IV MaNGA survey

ABSTRACT Massive red spiral galaxies (MRSGs) are supposed to be the possible progenitors of lenticular galaxies (S0s). We select a large sample of MRSGs ($M_*\gt 10^{10.5}\rm {\rm M}_{\odot }$) from Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) DR17 using the g − r colour versus stellar mass diagram, along with control samples of blue spirals and S0s. Our main results are as follows: (1) After comparing the Sérsic index, concentration parameter, asymmetry parameter distribution, size–mass relation, and Σ1 (stellar mass surface density within the central 1 kpc)−mass relation, we find MRSGs are similar to S0s and have more compact and symmetric structures than blue spirals. MRSGs also resemble S0s in Dn4000, metallicity, Mgb/$\rm \left\langle Fe \right\rangle$, and V/σ radial profile. (2) By using MaNGA 2D spectra data, we separate the spatial regions into inner (R < 0.8Re) and outer (0.8 < R < 1.5Re) regions, and detect residual star formation in the outer regions of MRSGs. (3) When we select a sub-sample of MRSGs with NUV − r > 5, we find that they are completely star formation quenched in both inner and outer regions. Compared to optically selected MRSGs, NUV − r selected MRSGs appear to be more concentrated and have more massive dark matter haloes. The similarities between S0s and MRSGs suggest the possible evolutionary trend between MRSGs and S0s.

Specific star formation rates in the Mbh-M*,sph diagram and the evolutionary pathways of galaxies across the sSFR-M* diagram

ABSTRACT It has been suggested that the bulge-to-total stellar mass ratio or feedback from black holes (BHs), traced by the BH-to-(total stellar) mass ratio, might establish a galaxy’s specific star formation rate (sSFR). We reveal that a galaxy’s morphology – reflecting its formation history, particularly accretions and mergers – is a far better determinant of the sSFR. Consequently, we suggest that galaxy formation models which regulate the sSFR primarily through BH feedback prescriptions or bulge-regulated disc fragmentation consider acquisitions and mergers which establish the galaxy morphology. We additionally make several new observations regarding current (z ∼ 0) star-formation rates. (i) Galaxies with little to no star formation have bulges with an extensive range of stellar masses; bulge mass does not dictate presence/absence on the ‘star-forming main sequence’. (ii) The (wet merger)-built, dust-rich S0 galaxies are the ‘green valley’ bridging population between elliptical galaxies on the ‘red sequence’ and spiral galaxies on the blue star-forming main sequence. (iii) The dust-poor S0 galaxies are not on the star-forming main sequence nor in the ‘green valley’. Instead, they wait in the field for gas accretion and/or minor mergers to transform them into spiral galaxies. Mid-infrared sample selection can miss these (primordial) low dust-content and low stellar-luminosity S0 galaxies. Finally, the appearance of the quasi-triangular-shaped galaxy-assembly sequence, previously dubbed the `Triangal', which tracks the morphological evolution of galaxies, is revealed in the sSFR-(stellar mass) diagram.

Tinjauan Inventori Daur Hidup dalam Pengelolaan Mineral Ikutan Radioaktif

Naturally-Occurring Radioactive Material (NORM) is generated by several non-nuclear activities or events. Life cycle assessment can be used to evaluate the steps and processes in managing NORM. However, the use of life cycle assessment for NORM is still limited. This paper aims to identify the key considerations when conducting a life cycle inventory analysis for NORM management. The life cycle assessment process includes determining objectives and scope, performing a life cycle inventory analysis, impact assessment, and interpretation. Since NORM is produced by a wide range of activities, it is essential to establish clear objectives and scope from the outset. Analysis of NORM management inventories will vary depending on the physical, chemical, or radionuclide characteristics of the NORM. One of the main challenges in inventory analysis is collecting data and information related to the input, process, and output of a processing unit based on the objectives and scope. Some general considerations that can be used in inventory analysis include determining flow and mass diagrams, location, and equipment data. Flow and mass diagrams show the input, process, and output stages of a processing unit, while location data can be used as a constraint in the life cycle assessment system. Equipment data will contain information regarding the type and number of equipment, equipment performance details, energy requirements, fuel requirements, etc. Inventory analysis can only be carried out accurately and effectively when the objectives and scope of the NORM management life cycle assessment are known. However, even if the processing unit and NORM management characteristics influence the input and output information and data, initial information regarding energy and fuel sources can still be analyzed. Keywords: radioactive minerals, life cycle assessment, NORM analysis, inventory.

The PAU survey: classifying low-z SEDs using Machine Learning clustering

ABSTRACT We present an application of unsupervised Machine Learning clustering to the PAU survey of galaxy spectral energy distribution (SED) within the COSMOS field. The clustering algorithm is implemented and optimized to get the relevant groups in the data SEDs. We find 12 groups from a total number of 5234 targets in the survey at 0.01 < z < 0.28. Among the groups, 3545 galaxies (68 per cent) show emission lines in the SEDs. These groups also include 1689 old galaxies with no active star formation. We have fitted the SED to every single galaxy in each group with CIGALE. The mass, age, and specific star formation rates (sSFR) of the galaxies range from 0.15 < age/Gyr <11; 6 < log (M⋆/M⊙) <11.26, and −14.67 < log (sSFR/yr−1) <−8. The groups are well-defined in their properties with galaxies having clear emission lines also having lower mass, are younger and have higher sSFR than those with elliptical like patterns. The characteristic values of galaxies showing clear emission lines are in agreement with the literature for starburst galaxies in COSMOS and GOODS-N fields at low redshift. The star-forming main sequence, sSFR versus stellar mass and UVJ diagram show clearly that different groups fall into different regions with some overlap among groups. Our main result is that the joint of low- resolution (R ∼ 50) photometric spectra provided by the PAU survey together with the unsupervised classification provides an excellent way to classify galaxies. Moreover, it helps to find and extend the analysis of extreme ELGs to lower masses and lower SFRs in the local Universe.

Imprints of Casimir wormhole in Einstein Gauss–Bonnet gravity with non-vanishing complexity factor

This article investigates Casimir wormhole solutions in Einstein Gauss–Bonnet (EGB) gravity. We are familiar that Null energy conditions (NEC) need not be satisfied for a stable wormhole due to the existence of exotic matter. As the Casimir effect acts as a negative energy source, it can be treated as a classical applicant for the exotic matter to discuss the stable dynamics of the wormhole. This work explores the Casimir effects with the Generalized Uncertainty Principle (GUP) on wormhole geometry in EGB gravity by confining our results for D=5. We have examined two GUP procedures, e.g., Kempf, Mangano, Mann (KMM) and Dentournay, Gabriel, and Spindel (DGS). We have developed shape functions for Casimir wormholes, and GUP corrected Casimir wormholes and studied their existence. In addition, we investigate the behavior of the Gauss–Bonnet (GB) Coupled parameter and minimal uncertainty (MU) parameter on the Equation of state (EOS) parameter. The active gravitational mass and embedding diagrams for all developed shape functions are analysed. Moreover, the violation of the NEC by an exotic matter, the equilibrium forces, and the complexity factor of Casimir wormholes and GUP-corrected Casimir wormholes have also been explored.

A crystallizing white dwarf in a sirius-like quadruple system

ABSTRACT The observational signature of core crystallization of white dwarfs has recently been discovered. However, the magnitude of the crystallization-powered cooling delay required to match observed white dwarfs is larger than predicted by conventional models, requiring additional mechanisms of energy release in white dwarf interiors. The most ideal benchmarks for understanding this discrepancy would be bright and nearby crystallizing white dwarfs with total ages that can be externally constrained. In this work, we report that a recently discovered white dwarf is a bound companion to the triple star HD 190412, forming a new Sirius-like system in the solar neighbourhood. The location of HD 190412 C on the Teff − mass diagram implies it is undergoing crystallization, making this the first confirmed crystallizing white dwarf whose total age can be externally constrained. Motivated by the possibility that a cooling delay caused by crystallization can be directly detected for this white dwarf we employ a variety of methods to constrain the age of the system; however, our empirical age anomaly of +3.1 ± 1.9 Gyr is ultimately too imprecise to reach statistical significance, preventing us from making strong constraints to models of white dwarf crystallization. Our results are none the less compatible with the recent hypothesis that 22Ne phase separation is responsible for the excess cooling delay of crystallizing white dwarfs. The discovery of this system at only 32 parsecs suggests that similar benchmark systems are likely to be common; future discoveries may therefore provide powerful tests for models of white dwarf crystallization.

Resequencing the Hubble sequence and the quadratic (black hole mass)–(spheroid stellar mass) relation for elliptical galaxies

ABSTRACT One of the most protracted problems in astronomy has been understanding the evolution of galaxy morphology. Much discussion has surrounded how lenticular galaxies may form a bridging population between elliptical and spiral galaxies. However, with recourse to a galaxy’s central black hole mass, accretion-built spiral galaxies have emerged as the bridging population between low-mass lenticular galaxies and the dusty merger-built lenticular galaxies contiguous with elliptical galaxies and ‘brightest cluster galaxies’ in the black hole/galaxy mass diagram. Spiral galaxies, including the Milky Way, appear built from gas accretion and minor mergers onto what were initially lenticular galaxies. These connections are expressed as a new morphology sequence, dubbed the ‘Triangal’, which subsumes elements of the Hubble sequence and the van den Bergh trident and reveals the bridging nature of the often overlooked ellicular galaxies. Furthermore, a quadratic black hole/galaxy mass relation is found to describe ordinary elliptical galaxies. The relation is roughly parallel to the quadratic-like relations observed for the central spheroidal component of spiral galaxies, dust-rich lenticular galaxies, and old dust-poor lenticular galaxies. The brightest cluster galaxies are offset according to expectations from an additional major merger. The findings have implications for feedback from active galactic nuclei, mapping morphology into simulations, and predicting gravitational wave signals from colliding supermassive black holes. A new galaxy speciation model is presented. It disfavours the ‘monolithic collapse’ scenario for spiral, dusty lenticular, and elliptical galaxies. It reveals substantial orbital angular momentum in the Universe’s first galaxies and unites dwarf and ordinary ‘early-type’ galaxies.

High-fidelity reproduction of central galaxy joint distributions with neural networks

ABSTRACT The relationship between galaxies and haloes is central to the description of galaxy formation and a fundamental step towards extracting precise cosmological information from galaxy maps. However, this connection involves several complex processes that are interconnected. Machine Learning methods are flexible tools that can learn complex correlations between a large number of features, but are traditionally designed as deterministic estimators. In this work, we use the IllustrisTNG300-1 simulation and apply neural networks in a binning classification scheme to predict probability distributions of central galaxy properties, namely stellar mass, colour, specific star formation rate, and radius, using as input features the halo mass, concentration, spin, age, and the overdensity on a scale of 3 h−1 Mpc. The model captures the intrinsic scatter in the relation between halo and galaxy properties, and can thus be used to quantify the uncertainties related to the stochasticity of the galaxy properties with respect to the halo properties. In particular, with our proposed method, one can define and accurately reproduce the properties of the different galaxy populations in great detail. We demonstrate the power of this tool by directly comparing traditional single-point estimators and the predicted joint probability distributions, and also by computing the power spectrum of a large number of tracers defined on the basis of the predicted colour–stellar mass diagram. We show that the neural networks reproduce clustering statistics of the individual galaxy populations with excellent precision and accuracy.

Triage of theGaiaDR3 astrometric orbits – I. A sample of binaries with probable compact companions

AbstractIn preparation for the release of the astrometric orbits of Gaia, Shahaf et al. (2019) proposed a triage technique to identify astrometric binaries with compact companions based on their astrometric semimajor axis, parallax, and primary mass. The technique requires the knowledge of the appropriate mass–luminosity relation to rule out single or close-binary main-sequence companions. The recent publication of the Gaia DR3 astrometric orbits used a schematic version of this approach, identifying 735 astrometric binaries that might have compact companions. In this communication, we return to the triage of the DR3 astrometric binaries with more careful analysis, estimating the probability for its astrometric secondary to be a compact object or a main-sequence close binary. We compile a sample of 177 systems with highly probable non-luminous massive companions, which is smaller but cleaner than the sample reported in Gaia DR3. The new sample includes eight candidates to be black-hole systems with compact-object masses larger than 2.4 M⊙. The orbital–eccentricity–secondary–mass diagram of the other 169 systems suggests a tentative separation between the white-dwarf and the neutron-star binaries. Most white-dwarf binaries are characterized by small eccentricities of about 0.1 and masses of 0.6 M⊙, while the neutron star binaries display typical eccentricities of 0.4 and masses of 1.3 M⊙.

Aging of galaxies along the morphological sequence, marked by bulge growth and disk quenching

Aims. We revisit the color bimodality of galaxies using the extensive EFIGI morphological classification of nearby galaxies. Methods. The galaxy profiles from the Sloan Digital Sky Survey (SDSS) gri images were decomposed as a bulge and a disk by controlled profile modeling with the Euclid SourceXtractor++ software. The spectral energy distributions from our resulting gri SDSS photometry complemented with Galaxy Evolution Explorer (GALEX) NUV photometry were fitted with the ZPEG software and PEGASE.2 templates in order to estimate the stellar masses and specific star formation rates (sSFR) of whole galaxies as well as their bulge and disk components. Results. The absolute NUV−r color versus stellar mass diagram shows a continuous relationship between the present sSFR of galaxies and their stellar mass, which spans all morphological types of the Hubble sequence monotonously. Irregular galaxies to intermediate-type Sab spirals make up the “Blue Cloud” across 4 orders of magnitude in stellar mass but a narrow range of sSFR. This mass build-up of spiral galaxies requires major mergers, in agreement with their frequently perturbed isophotes. At high mass, the Blue Cloud leads to the “Green Plain”, dominated by S0a and Sa early-type spirals. It was formerly called the “Green Valley”, due to its low density, but we rename it because of its wide stretch and nearly flat density over ∼2 mag in NUV−r color (hence sSFR), despite a limited range of stellar mass (1 order of magnitude). The Green Plain links up the “Red Sequence”, containing all lenticular and elliptical galaxies with a 2 order of magnitude mass interval, and systematically higher masses for the ellipticals. We confirm that the Green Plain cannot be studied using u − r optical colors because it is overlayed by the Red Sequence, hence NUV data are necessary. Galaxies across the Green Plain undergo a marked growth by a factor 2 to 3 in their bulge-to-total mass ratio and a systematic profile change from pseudo to classical bulges, as well as a significant reddening due to star formation fading in their disks. The Green Plain is also characterized by a maximum stellar mass of 1011.7 M⊙ beyond which only elliptical galaxies exist, hence supporting the scenario of ellipticals partly forming by major mergers of massive disk galaxies. Conclusions. The EFIGI attributes indicate that dynamical processes (spiral arms and isophote distortions) contribute to the scatter of the Main Sequence of star-forming galaxies (Blue Cloud), via the enhancement of star formation (flocculence, HII regions). The significant bulge growth across the Green Plain confirms that it is a transition region, and excludes a predominantly quick transit due to rapid quenching. The high frequency of bars for all spirals as well as the stronger spiral arms and flocculence in the knee of the Green Plain suggest that internal dynamics, likely triggered by flybys or (mainly minor) mergers, may be the key to the bulge growth of massive disk galaxies, which is a marker of the aging of galaxies from star forming to quiescence. The Hubble sequence can then be considered as an inverse sequence of galaxy physical evolution.

COSMOS2020: Manifold learning to estimate physical parameters in large galaxy surveys

We present a novel method for estimating galaxy physical properties from spectral energy distributions (SEDs) as an alternative to template fitting techniques and based on self-organizing maps (SOMs) to learn the high-dimensional manifold of a photometric galaxy catalog. The method has previously been tested with hydrodynamical simulations in Davidzon et al. (2019, MNRAS, 489, 4817), however, here it is applied to real data for the first time. It is crucial for its implementation to build the SOM with a high-quality panchromatic data set, thus we selected “COSMOS2020” galaxy catalog for this purpose. After the training and calibration steps with COSMOS2020, other galaxies can be processed through SOMs to obtain an estimate of their stellar mass and star formation rate (SFR). Both quantities resulted in a good agreement with independent measurements derived from more extended photometric baseline and, in addition, their combination (i.e., the SFR vs. stellar mass diagram) shows a main sequence of star-forming galaxies that is consistent with the findings of previous studies. We discuss the advantages of this method compared to traditional SED fitting, highlighting the impact of replacing the usual synthetic templates with a collection of empirical SEDs built by the SOM in a “data-driven” way. Such an approach also allows, even for extremely large data sets, for an efficient visual inspection to identify photometric errors or peculiar galaxy types. While also considering the computational speed of this new estimator, we argue that it will play a valuable role in the analysis of oncoming large-area surveys such as Euclid of the Legacy Survey of Space and Time at the Vera C. Rubin Telescope.

How many 1-loop neutrino mass models are there?

It is well-known that at tree-level the d = 5 Weinberg operator can be generated in exactly three different ways, the famous seesaw models. In this paper we study the related question of how many phenomenologically consistent 1-loop models one can construct at d=5. First, we discuss that there are two possible classes of 1-loop neutrino mass models, that allow avoiding stable charged relics: (i) models with dark matter candidates and (ii) models with “exits”. Here, we define “exits” as particles that can decay into standard model fields. Considering 1-loop models with new scalars and fermions, we find in the dark matter class a total of (115+203) models, while in the exit class we find (38+368) models. Here, 115 is the number of DM models, which require a stabilizing symmetry, while 203 is the number of models which contain a dark matter candidate, which maybe accidentally stable. In the exit class the 38 refers to models, for which one (or two) of the internal particles in the loop is a SM field, while the 368 models contain only fields beyond the SM (BSM) in the neutrino mass diagram. We then study the RGE evolution of the gauge couplings in all our 1-loop models. Many of the models in our list lead to Landau poles in some gauge coupling at rather low energies and there is exactly one model which unifies the gauge couplings at energies above 1015 GeV in a numerically acceptable way.

Host galaxy magnitude of OJ 287 from its colours at minimum light

ABSTRACTOJ 287 is a BL Lacertae type quasar in which the active galactic nucleus (AGN) outshines the host galaxy by an order of magnitude. The only exception to this may be at minimum light when the AGN activity is so low that the host galaxy may make quite a considerable contribution to the photometric intensity of the source. Such a dip or a fade in the intensity of OJ 287 occurred in 2017 November, when its brightness was about 1.75 mag lower than the recent mean level. We compare the observations of this fade with similar fades in OJ 287 observed earlier in 1989, 1999, and 2010. It appears that there is a relatively strong reddening of the B− V colours of OJ 287 when its V-band brightness drops below magnitude 17. Similar changes are also seen in V− R, V− I, and R− I colours during these deep fades. These data support the conclusion that the total magnitude of the host galaxy is V = 18.0 ± 0.3, corresponding to MK = −26.5 ± 0.3 in the K-band. This is in agreement with the results, obtained using the integrated surface brightness method, from recent surface photometry of the host. These results should encourage us to use the colour separation method also in other host galaxies with strongly variable AGN. In the case of OJ 287, both the host galaxy and its central black hole are among the biggest known, and its position in the black hole mass–galaxy mass diagram lies close to the mean correlation.

The luminosity of cluster galaxies in the Cluster-EAGLE simulations

ABSTRACT We computed the luminosity of simulated galaxies of the c-eagle project, a suite of 30 high-resolution zoom-in simulations of galaxy clusters based on the eagle simulation. The AB magnitudes are derived for different spectral bands, from ultraviolet to infrared, using the simple stellar population modelling based on the E-MILES stellar spectra library. We take into account obscuration due to dust in star forming regions and diffuse interstellar medium. The g − r colour–stellar mass diagram, at z = 0.1, presents a defined red sequence, reaching g − r ≃ 0.8, 0.05 dex redder than eagle at high masses, and a well populated blue cloud, when field galaxies are included. The clusters’ inner regions are dominated by red-sequence galaxies at all masses, although a non-negligible amount of blue galaxies are still present. We adopt Bayesian inference to compute the clusters LFs, testing for statistical significance of both single and double Schechter functions. The multicolour LFs at z = 0 show a knee luminosity that peaks in the infrared and increases with the cluster’s mass. The faint-end is weakly dependent on colour and mass and shows an upturn in the optical, bounded between −1.25 and −1.39, just moderately steeper than the field. The simulations reproduce, within the observational errors, the spectroscopic LFs of the Hercules and Abell 85 clusters, including their faint end upturn. c-eagle LFs are in broad agreement with observed LFs taken from SDSS and XXL surveys, up to z = 0.67, showing a rather flat faint end when the observational constrains are taken into account.

Water footprint comparison of a naphtha-fired combined cycle power plant and a coal-fired steam power plant.

The vulnerability of the power generation industries vulnerability to the availability of water is widespread and growing. In this regard, water footprint (WF) is one method to assess this challenge. The present study conducts the WF of a naphtha-fired combined cycle power plant (CCPP) and a coal-fired steam power plant (CSPP). For carrying out WF, it is prudent to look after water consumption during operations and the supply chain stages. Hence, in this regard, two methods have been adopted to investigate the WF of both power plants. The first method deals with the water balance mass diagram (direct WF), and the second method deals with the water supply chain (indirect WF). Evaporation loss appears to be a significant contributing factor to the direct WF. On the other hand, operational WF seems to be an essential contributing factor to indirect WF. Furthermore, the result also shows that specific water consumption in CSPP is 3.54 m3/h, whereas, in CCPP, it is 0.9 m3/h. Finally, some methods have also been suggested to reduce WF in both power plants.