Bright Regime Research Articles

TheGaia-ESO Survey DR5.1 andGaiaDR3 GSP-Spec: a comparative analysis

Context.The third data release ofGaia,has provided stellar parameters, metallicity [M/H], [α/Fe], individual abundances, broadening parameter from its Radial Velocity Spectrograph (RVS) spectra for about 5.6 million objects thanks to the GSP-Spec module, implemented in theGaiapipeline. The catalogue also publishes the radial velocity of 33 million sources. In recent years, many spectroscopic surveys with ground-based telescopes have been undertaken, including the public surveyGaia-ESO, designed to be complementary toGaia,in particular towards faint stars.Aims.We took advantage of the intersections betweenGaiaRVS andGaia-ESO to compare their stellar parameters, abundances and radial and rotational velocities. We aimed at verifying the overall agreement between the two datasets, considering the various calibrations and the quality-control flag system suggested for theGaiaGSP-Spec parameters.Methods.For the targets in common betweenGaiaRVS andGaia-ESO, we performed several statistical checks on the distributions of their stellar parameters, abundances and velocities of targets in common. For theGaiasurface gravity and metallicity we considered both the uncalibrated and calibrated values.Results.Overall, there is a good agreement between the results of the two surveys. We find an excellent agreement between theGaiaandGaia-ESO radial velocities given the uncertainties affecting each dataset. Less than 25 out of the ≈2100Gaia-ESO spectroscopic binaries are flagged as non-single stars byGaia.For the effective temperature and in the bright regime (G≤ 11), we found a very good agreement, with an absolute residual difference of about 5 K (±90 K) for the giant stars and of about 17 K (±135 K) for the dwarf stars; in the faint regime (G≥ 11), we found a worse agreement, with an absolute residual difference of about 107 K (±145 K) for the giant stars and of about 103 K (±258 K) for the dwarf stars. For the surface gravity, the comparison indicates that the calibrated gravity should be preferred to the uncalibrated one. For the metallicity, we observe in both the uncalibrated and calibrated cases a slight trend wherebyGaiaoverestimates it at low metallicity; for [M/H] and [α/Fe], a marginally better agreement is found using the calibratedGaiaresults; finally for the individual abundances (Mg, Si, Ca, Ti, S, Cr, Ni, Ce) our comparison suggests to avoid results with flags indicating low quality (XUncer = 2 or higher). These remarks are in line with the ones formulated by GSP-Spec. We confirm that theGaiavbroad parameter is loosely correlated with theGaia-ESOvsinifor slow rotators. Finally, we note that the quality (accuracy, precision) of the GSP-Spec parameters degrades quickly for objects fainter thanG≈ 11 orGRVS≈ 10.Conclusions.We find that the somewhat imprecise GSP-Spec abundances due to its medium-resolution spectroscopy over a short wavelength window and the faintGregime of the sample under study can be counterbalanced by working with averaged quantities. We extended our comparison to star clusters using averaged abundances, using not only the stars in common, but also the members of clusters in common between the two samples, still finding a very good agreement. Encouraged by this result, we studied some properties of the open-cluster population, using bothGaia-ESO andGaiaclusters: our combined sample traces very well the radial metallicity and [Fe/H] gradients, the age-metallicity relations in different radial regions, and allows us to place the clusters in the thin disc.

The PAU Survey: The quasar and UV luminosity functions at 2.7<z<5.3

We present the Lyman-alpha ( and ultraviolet (UV) luminosity function (LF) in bins of redshift for quasars selected in the Physics of the Accelerating Universe Survey (PAUS). A sample of 915 objects was selected at $2.7<z<5.3$ within an effective area of $ 36$ deg$^2$ observed in 40 narrow-band (NB) filters (FWHM $ We cover the intermediate--bright luminosity regime of the LF erg\,s $; $-29<M_ UV <-24$). The continuous wavelength coverage of the PAUS NB set allows very efficient target identification and precise redshift measurements. We show that our method is able to retrieve a relatively complete ($C 85<!PCT!>$) and pure ($P 90<!PCT!>$) sample of quasars for $ $. In order to obtain corrections for the LF estimation, and assess the accuracy of our selection method, we produced mock catalogs of $0<z<4.3$ quasars and galaxies that mimic our target population and their main contaminants. Our results show a clear evolution of the and UV LFs, with a declining tendency in the number density of quasars toward increasing redshifts. In addition, the faint-end power-law slope of the LF becomes steeper with redshift, suggesting that the number density of quasars declines faster than that of fainter emitters. By integrating the LF, we find that the total emitted by bright quasars per unit volume rapidly declines with increasing redshift, being subdominant to that of star-forming galaxies by several orders of magnitude by $z 4$. Finally, we stack the NB pseudo-spectra of a visually selected ``golden sample'' of 591 quasars to obtain photometric composite SEDs in bins of redshift, enabling us to measure the mean intergalactic medium absorption using the Lyman-alpha forest as a function of redshift, yielding results consistent with previous spectroscopic determinations.

Strategies for optimal sky subtraction in the low surface brightness regime

ABSTRACT The low surface brightness (LSB) regime (μg ≳ 26 mag arcsec−2) comprises a vast, mostly unexplored discovery space, from dwarf galaxies to the diffuse interstellar medium. Accessing this regime requires precisely removing instrumental signatures and light contamination, including, most critically, night sky emission. This is not trivial, as faint astrophysical and instrumental contamination can bias sky models at the precision needed to characterize LSB structures. Using idealized synthetic images, we assess how this bias impacts two common LSB-oriented sky-estimation algorithms: (1) masking and parametric modelling, and (2) stacking and smoothing dithered exposures. Undetected flux limits both methods by imposing a pedestal offset to all derived sky models. Careful, deep masking of fixed sources can mitigate this, but source density always imposes a fundamental limit. Stellar scattered light can contribute ∼28–29 mag arcsec−2 of background flux even in low-density fields; its removal is critical prior to sky estimation. For complex skies, image combining is an effective non-parametric approach, although it strongly depends on observing strategy and adds noise to images on the smoothing kernel scale. Preemptive subtraction of fixed sources may be the only practical approach for robust sky estimation. We thus tested a third algorithm, subtracting a preliminary sky-subtracted coadd from exposures to isolate sky emission. Unfortunately, initial errors in sky estimation propagate through all subsequent sky models, making the method impractical. For large-scale surveys like Legacy Survey of Space and Time, where key science goals constrain observing strategy, masking and modelling remain the optimal sky estimation approach, assuming stellar scattered light is removed first.

Navigating The New Loper Bright Regime

Navigating The New Loper Bright Regime

The AMIGA sample of isolated galaxies

Context. In the standard cosmological model of galaxy evolution, mergers and interactions play a fundamental role in shaping galaxies. Galaxies that are currently isolated are thus interesting because they allow us to distinguish between internal and external processes that affect the galactic structure. However, current observational limits may obscure crucial information in the low-mass or low-brightness regime. Aims. We use optical imaging of a subsample of the AMIGA catalogue of isolated galaxies to explore the impact of different factors on the structure of these galaxies. In particular, we study the type of disc break as a function of the degree of isolation and the presence of interaction indicators such as tidal streams or plumes, which are only detectable in the ultra-low surface brightness regime. Methods. We present ultra-deep optical imaging in the r band of a sample of 25 low-redshift (z < 0.035) isolated galaxies. Through careful data processing and analysis techniques, the nominal surface brightness limits achieved are comparable to those to be obtained on the ten-year LSST coadds (μr,lim ≳ 29.5 mag arcsec−2 [3σ; 10″ × 10″]). We place special emphasis on preserving the low surface brightness features throughout the processing. Results. The extreme depth of our imaging allows us to study the interaction signatures of 20 galaxies since Galactic cirrus is a strong limiting factor in the characterisation of interactions for the remaining 5 of them. We detect previously unreported interaction features in 8 (40% ± 14%) galaxies in our sample. We identify 9 galaxies (36% ± 10%) with an exponential disc (Type I), 14 galaxies (56% ± 10%) with a down-bending (Type II) profile, and only 2 galaxies (8% ± 5%) with up-bending (Type III) profiles. Isolated galaxies have considerably more purely exponential discs and fewer up-bending surface brightness profiles than field or cluster galaxies. We find clear minor merger activity in some of the galaxies with single exponential or down-bending profiles, and both of the galaxies with up-bending profiles show signatures of a past interaction. Conclusions. We show the importance of ultra-deep optical imaging in revealing faint external features in galaxies that indicate a probable history of interaction. We confirm that up-bending profiles are likely produced by major mergers, while down-bending profiles are probably formed by a threshold in star formation. Unperturbed galaxies that slowly evolve with a low star formation rate could induce the high rate of Type I discs in isolated galaxies.

Temporal electric field and electron density behavior of a He plasma jet with pulse width closing to pulse duration

Previously, it was observed that the plasma plume appears with three regimes (dark regime next to the nozzle, bright regime in the middle, and dim regime on the right) where the regime next to the nozzle is dark when the pulse width of the applied voltage is close to the pulse duration. In this paper, to understand such observation, the spatial and temporal resolved electron density and electric field in the three regimes are measured through the Thomson scattering and electric field-induced second harmonic method, respectively. It is found that, in the dark regime next to the nozzle, the electric field is relatively low, and it has a peak value of about 10 kV/cm, but the electron density is high, and it has a peak value of about 4.2 × 1020 m−3. So, the dark regime is like a conductive channel. On the other hand, for the bright regime, the electric field is much higher, and it has a peak value of about 17 kV/cm. However, the electron density is significantly lower than that in the dark regime, and its peak value is only about 1020 m−3. Even in the dim regime, the electric field is higher than that in the dark regime, and it has a peak value of about 13 kV/cm. Because electron temperature is related to the electric field, the results obtained in the paper indicate that the brightness of the plasma plume at different regimes is mainly decided by the electron temperature rather than the electron density. Finally, when a trace amount of O2 is mixed into working gas He, the dark regime disappears, and this is believed to be due to the fast attachment of electron to O2, which results in the decrease in the residual electron density in the regime next to the nozzle.

Lessons learned from the two largest Galaxy morphological classification catalogues built by convolutional neural networks

ABSTRACT We compare the two largest galaxy morphology catalogues, which separate early- and late-type galaxies at intermediate redshift. The two catalogues were built by applying supervised deep learning (convolutional neural networks, CNNs) to the Dark Energy Survey data down to a magnitude limit of ∼21 mag. The methodologies used for the construction of the catalogues include differences such as the cutout sizes, the labels used for training, and the input to the CNN – monochromatic images versus gri-band normalized images. In addition, one catalogue is trained using bright galaxies observed with DES (i < 18), while the other is trained with bright galaxies (r < 17.5) and ‘emulated’ galaxies up to r-band magnitude 22.5. Despite the different approaches, the agreement between the two catalogues is excellent up to i < 19, demonstrating that CNN predictions are reliable for samples at least one magnitude fainter than the training sample limit. It also shows that morphological classifications based on monochromatic images are comparable to those based on gri-band images, at least in the bright regime. At fainter magnitudes, i > 19, the overall agreement is good (∼95 per cent), but is mostly driven by the large spiral fraction in the two catalogues. In contrast, the agreement within the elliptical population is not as good, especially at faint magnitudes. By studying the mismatched cases, we are able to identify lenticular galaxies (at least up to i < 19), which are difficult to distinguish using standard classification approaches. The synergy of both catalogues provides an unique opportunity to select a population of unusual galaxies.

Ecological and coenotic groups of Southern Trans-Urals vascular plants flora and biotopes phytoindication

The expert and statistical assessment of ecological and coenotic groups of Southern Trans-Urals vascular plants flora has been done for A.L. Belgards coenomorphs scheme and scheme of vascular plants flora of temperate forest zone of European Russia. Both suggested schemes of groups give adequate and similar assessment of biotopes. The proposed groups of vascular plants flora are identified in phytometer scales space definitely and can be used for regional assessment of biotopes. The best assessment of ecological flora of region is realized by combined coenomorphs and coenotic group schemes approach at the same time. The authors have established regimes of principal ecological factors that identified differentiation flora by coenotic groups and ultimate for specific groups forming in Southern Trans-Urals habitats. Sylvant coenomorph has been formed by boreal (acidic soils phytometers) and nemoral sciophytes and heliosciophytes, moreover a nemoral group must be understood as a group of shady forests on rich soils. The sylvant pine forest group is heterogeneous and not coenoticaly specific. The steppe coenotic group has been formed of obligate and facultative heliophytes of mostly dry biotopes, pratal coenomorph is heterogeneous and not coenoticaly specific and made up of humidity-meadow flora, dry-meadow coenotic group is not specific. For Southern Trans-Urals region it is recommended to use unite paludal coenomorphs but with a separation of coenotic group of oligotrophic bogs. The separation of ruderal coenomorph (phytometers of dry-meadow moistening and rich of nitrogen soils) is confirmed statistically. The authors have established regimes of principal ecological factors for stenotopic ecological and coenotic groups of Southern Trans-Urals region. For coenotic groups of Southern Trans-Urals region the authors have identified biotopical centres and biotopic and coenotic series which are associated with moistening, aeration and saline soil conditions and brightness regime.

Vegetation of regional landscape and botanical natural monument «Aland’s Pine Forest» (Kvarkensky area of the Orenburg Region)

The paper presents a detailed analysis of regional landscape and botanical natural monument Alands Pine Forest (Kvarkensky area of the Orenburg Region) vegetation. The pine forest vegetation has rather high phytodiversity and dominance indexes. 71 plant vascular species have been identified (3 of them are included in the Red Book of the Orenburg Region (2019)) and 15-species pine communities prevail, but steppe species dominate in shrub and herb layers. The authors have revealed that the described pine forests are forest-steppe amphycoenosis. 13 plant associations have been identified by multivariate statistics methods, but their biotopes are not specific by fundamental abiotic factors. The authors have also established that forest conditions of Alands Pine Forest are of AB₁ and AB₁₋₂ types and light type of stand of trees structure by A.L. Betgard steppe forest typology. The detected pine vegetation associations form ordination series - sylvatic of steppe pine forest with wheat-grass ( Elytrigia repens (L.) Nevski) and amphycoenotic of steppe pine forest with steppe herbs. The principal abiotic factors for pine forests coenotic structure forming are soil calcium and nitrogen regimes, soil moistening and acidity and porosity (aeration) of soils. Factors of biotope discrimination are thermal climate (radiation balance), cryoclimate (negative winter temperature), brightness regime and saline regime of soils.

Heartbeat instability as auto-oscillation between dim and bright void regimes.

We investigated the self-excited as well as optogalvanically stimulated heartbeat instability in RF discharge complex plasma. Three video cameras measured the motion of the microparticles, the plasma emission, and the laser-induced fluorescence simultaneously. Comprehensive studies of the optogalvanic control of the heartbeat instability revealed that the microparticle suspension can be stabilized by a continuous laser, whereas a modulated laser beam induces the void contraction either transiently or resonantly. The resonance occurred when the laser modulation frequency coincided with the frequency of small breathing oscillations of the microparticle suspension, which are known to be a prerequisite to the heartbeat instability. Based on the experimental results we suggest that the void contraction during the instability is caused by an abrupt void transition from the dim to the bright regime [Pikalev et al., Plasma Sources Sci. Technol. 30, 035014 (2021)PSTEEU0963-025210.1088/1361-6595/abe0a2]. In the bright regime, a time-averaged electric field at the void boundary heats the electrons causing bright plasma emission inside the void. The dim void has much lower electric field at the boundary and exhibits therefore no emission feature associated with it.

Break type and interactions from ultra-deep optical imaging of isolated galaxies

AbstractIn the standard cosmological model of galaxy evolution, mergers and interactions play a fundamental role in shaping galaxies. Galaxies that are currently isolated are thus interesting, allowing us to identify how internal or external processes impact galactic structure. However, current observational limits may be obscuring crucial information in the low-mass or low-brightness regime. We use the AMIGA catalog of isolated galaxies to explore the impact of different factors on the structure of these galaxies. In particular, we study the type of disk break based on the degree of isolation and the presence of interactions which are only detectable in the ultra-low surface brightness regime. We present the first results of an extensive observational campaign of ultra-deep optical imaging targeting a sample of 25 low-redshift (z < 0.035) isolated galaxies. The nominal surface brightness limits achieved are comparable to those to be obtained in the 10-year LSST coadds ( mag arcsec−2; 3σ ; 10” × 10”). We find that isolated galaxies have a considerably higher fraction of purely exponential disk profiles and a lower presence of up-bending breaks than field or cluster galaxies. Our extreme imaging depth allows us to detect the presence of previously unreported interactions with minor companions in some of the galaxies in our sample (∼40% of the galaxies show signs of interaction). The results of our work fit with the general framework of galactic structure in which up-bending breaks (Type III) would be produced by mergers and down-bending breaks (Type II) due to a threshold in star formation that would tend to become single exponential disk (Type I) in case of cessation or decrease of star formation.

Versatile Super-Sensitive Metrology Using Induced Coherence

We theoretically analyze the phase sensitivity of the Induced-Coherence (Mandel-Type) Interferometer, including the case where the sensitivity is "boosted" into the bright input regime with coherent-light seeding. We find scaling which reaches below the shot noise limit, even when seeding the spatial mode which does not interact with the sample – or when seeding the undetected mode. It is a hybrid of a linear and a non-linear (Yurke-Type) interferometer, and aside from the supersensitivity, is distinguished from other systems by "preferring" an imbalance in the gains of the two non-linearities (with the second gain being optimal at low values), and non-monotonic behavior of the sensitivity as a function of the gain of the second non-linearity. Furthermore, the setup allows use of subtracted intensity measurements, instead of direct (additive) or homodyne measurements – a significant practical advantage. Bright, super-sensitive phase estimation of an object with different light fields for interaction and detection is possible, with various potential applications, especially in cases where the sample may be sensitive to light, or is most interesting in frequency domains outside what is easily detected, or when desiring bright-light phase estimation with sensitive/delicate detectors. We use an analysis in terms of general squeezing and discover that super-sensitivity occurs only in this case – that is, the effect is not present with the spontaneous-parametric-down-conversion approximation, which many previous analyses and experiments have focused on.

Dim and bright void regimes in capacitively-coupled RF complex plasmas

We demonstrate experimentally that the void in capacitively-coupled RF complex plasmas can exist in two qualitatively different regimes. The ‘bright’ void is characterized by bright plasma emission associated with the void, whereas the ‘dim’ void possesses no detectable emission feature. The transition from the dim to the bright regime occurs with an increase of the discharge power and has a discontinuous character. The discontinuity is manifested by a kink in the void size power dependencies. We reproduce the bright void (mechanically stabilized due to the balance of ion drag and electrostatic forces) by a simplified time-averaged 1D fluid model. To reproduce the dim void, we artificially include the radial ion diffusion into the continuity equation for ions, which allows to mechanically stabilize the void boundary due to very weak electrostatic forces. The electric field at the void boundary occurs to be so small that it, in accordance with the experimental observation, causes no void-related emission feature.

Difference in Chemical Composition between the Bright and Faint Red Clump Stars in the Milky Way Bulge

Abstract The double red clump (RC) observed in color–magnitude diagrams of the Milky Way bulge is at the heart of the current debate on the structure and formation origin of the bulge. This feature can be explained by the difference between the two RCs either in distance (“X-shaped scenario”) or in chemical composition (“multiple-population scenario”). Here we report our high-resolution spectroscopy for the RC and red giant branch stars in a high-latitude field (b ∼ −8.5°) of the bulge. We find a difference in [Fe/H] between the stars in the bright and faint RC regimes, in the sense that the bright stars are enhanced in [Fe/H] with respect to the faint stars by 0.149 ± 0.036 dex. The stars on the bright RC are also enhanced in [Na/Fe] but appear to be depleted in [Al/Fe] and [O/Fe], although more observations are required to confirm the significance of these differences. Interestingly, these chemical patterns are similar to those observed among multiple stellar populations in the metal-rich bulge globular cluster Terzan 5. In addition, we find a number of Na-rich stars, which would corroborate the presence of multiple populations in the bulge. Our results support an origin of the double RC from dissolved globular clusters that harbor multiple stellar populations. Thus, our study suggests that a substantial fraction of the outer bulge stars would have originated from the assembly of such stellar systems in the early phase of the Milky Way formation.

Impact of non-Gaussian beam profiles in the performance of hadron colliders

At the Large Hadron Collider (LHC), the interplay between a series of effects, including intrabeam scattering (IBS), synchrotron radiation, longitudinal beam manipulations, two beam effects (beam-beam, e-cloud) and machine non-linearities, can change the population of the core and tails and lead to non-Gaussian beam distributions, at different periods during the beam cycle. By employing generalised distribution functions, it can be demonstrated that the modified non-Gaussian beam profiles have an impact in the beam emittance evolution by itself and thereby to the collider luminosity. This paper focuses on the estimation of beam distribution modification and the resulting rms beam size due to the combined effect of IBS and synchrotron radiation by employing a Monte-Carlo simulation code which is able to track 3D generalised particle distributions (SIRE). The code is first benchmarked over classical semi-analytical IBS theories and then compared with measurements from the LHC at injection and collision energies, including projections for the High-Luminosity LHC (HL-LHC) high brightness regime. The impact of the distribution shape on the evolution of the bunch characteristics and machine performance is finally addressed.

Aerosols in OCO-2/GOSAT retrievals of XCO2: An information content and error analysis

We have analyzed the effect of aerosols on the retrieval of the dry air mixing ratio of carbon dioxide (XCO2) in the Earth's atmosphere from instruments like OCO-2 and GOSAT. High-fidelity simulations of multi-angle spectropolarimetric observations in the O2 A-band and the weak and strong CO2 bands are used to evaluate the information contained in different measurement subsets/synergies for the retrieval of aerosol, surface, and molecular parameters. We contrast the biases and uncertainties in the retrieved XCO2 resulting from the assumption of free or fixed aerosol microphysical parameters in the retrieval algorithm. It is very difficult to achieve the required retrieval accuracy of 0.2% for XCO2 using intensity-only Nadir mode measurements. The uncertainty in the retrieved XCO2 can be minimized by introducing multiangle and polarimetric measurement synergies. While the retrieval bias on XCO2 is practically eliminated by the addition of measurement synergies for free aerosol microphysical parameters, fixed aerosol retrievals can lead to an increase in XCO2 bias. In both cases, our full multi-angle polarimetric dataset produces a maximum uncertainty of ~1.6% in the retrieved XCO2 at low aerosol optical thicknesses and over dark surfaces. The XCO2 retrieval uncertainty improves to better than 0.2% at greater aerosol optical thickness and brighter surfaces. The problematic low aerosol optical thickness and low surface brightness regime produces an XCO2 bias of 1 − 8% for fixed aerosol microphysics, while the free parameters produce a maximum bias well under 10−3% for all retrieval scenes considered.

Early-type galaxies in the Antlia cluster: global properties

ABSTRACT We present an extension of our previous research on the early-type galaxy population of the Antlia cluster (d ∼ 35 Mpc), achieving a total coverage of ∼2.6 deg2 and performing surface photometry for ∼300 galaxies, 130 of which are new uncatalogued ones. Such new galaxies mainly fall in the low surface brightness (LSB) regime, but there are also some lenticulars (S0), which support the existence of unique functions that connect bright and dwarf galaxies in the scaling relations. We analyse the projected spatial distribution of galaxies up to a distance of ∼800 kpc from NGC 3268, the adopted centre, as well as the radial velocity distribution and the correlation between galaxy colour and effective radius with the projected spatial distribution. We also obtain the luminosity function of the early-type galaxies and the distribution of stellar masses using the T1-band magnitudes and adopted mass-luminosity ratios. Additionally, we correlate the central galaxy distribution with an X-ray emission map from the literature. Based on the analysis of the radial velocities and galaxy colour distributions, we find that galaxies redder than the colour–magnitude relation (CMR) have a velocity distribution strongly concentrated towards the values of the dominant galaxies and are homogeneously distributed throughout the cluster. Those bluer than the CMR, in turn, have a much more extended radial velocity distribution and are concentrated towards the centre of the cluster. We also identify 12 candidates to ultra diffuse galaxies, which seem to be split into two families, and speculate about their origins in the context of the cluster structure.

UV and U-band luminosity functions from CLAUDS and HSC-SSP – I. Using four million galaxies to simultaneously constrain the very faint and bright regimes to z ∼ 3

ABSTRACT We constrain the rest-frame FUV (1546 Å), NUV (2345 Å), and U-band (3690 Å) luminosity functions (LFs) and luminosity densities (LDs) with unprecedented precision from z ∼ 0.2 to z ∼ 3 (FUV, NUV) and z ∼ 2 (U band). Our sample of over 4.3 million galaxies, selected from the CFHT Large Area U-band Deep Survey (CLAUDS) and HyperSuprime-Cam Subaru Strategic Program (HSC-SSP) data lets us probe the very faint regime (down to MFUV, MNUV, MU ≃ −15 at low redshift), while simultaneously detecting very rare galaxies at the bright end down to comoving densities <10−5 Mpc−3. Our FUV and NUV LFs are well fitted by single-Schechter functions, with faint-end slopes that are very stable up to z ∼ 2. We confirm, but self-consistently and with much better precision than previous studies, that the LDs at all three wavelengths increase rapidly with lookback time to z ∼ 1, and then much more slowly at 1 < z < 2–3. Evolution of the FUV and NUV LFs and LDs at z < 1 is driven almost entirely by the fading of the characteristic magnitude, $M^\star _{\rm UV}$, while at z > 1 it is due to the evolution of both $M^\star _{\rm UV}$ and the characteristic number density $\phi ^\star _{\rm UV}$. In contrast, the U-band LF has an excess of faint galaxies and is fitted with a double-Schechter form; $M^\star _{U}$, both $\phi ^\star _{U}$ components, and the bright-end slope evolve throughout 0.2 < z < 2, while the faint-end slope is constant over at least the measurable 0.05 < z < 0.6. We present tables of our Schechter parameters and LD measurements that can be used for testing theoretical galaxy evolution models and forecasting future observations.

A PSF-based Approach to TESS High quality data Of Stellar clusters (PATHOS) – I. Search for exoplanets and variable stars in the field of 47 Tuc

ABSTRACT The TESS mission will survey ∼85 per cent of the sky, giving us the opportunity of extracting high-precision light curves of millions of stars, including stellar cluster members. In this work, we present our project ‘A PSF-based Approach to TESS High quality data Of Stellar clusters’ (PATHOS), aimed at searching and characterize candidate exoplanets and variable stars in stellar clusters using our innovative method for the extraction of high-precision light curves of stars located in crowded environments. Our technique of light-curve extraction involves the use of empirical point spread functions (PSFs), an input catalogue and neighbour-subtraction. The PSF-based approach allows us to minimize the dilution effects in crowded environments and to extract high-precision photometry for stars in the faint regime (G > 13). For this pilot project, we extracted, corrected, and analysed the light curves of 16 641 stars located in a dense region centred on the globular cluster 47 Tuc. We were able to reach the TESS magnitude T ∼ 16.5 with a photometric precision of ${\sim} 1{{\ \rm per\ cent}}$ on the 6.5-h time-scale; in the bright regime we were able to detect transits with depth of ∼34 parts per million. We searched for variables and candidate transiting exoplanets. Our pipeline detected one planetary candidate orbiting a main-sequence star in the Galactic field. We analysed the period–luminosity distribution for red-giant stars of 47 Tuc and the eclipsing binaries in the field. Light curves are uploaded on the Mikulski Archive for Space Telescopes under the project PATHOS.

Hydrodynamic model of a Bose–Einstein condensate with anisotropic short-range interaction and bright solitons in a repulsive Bose–Einstein condensate

A quantum hydrodynamic model is developed for axial symmetric anisotropic short-range interactions. The quantum stress tensor represents the interaction and is derived up to the third order by the interaction radius. The first order by the interaction radius contains the isotropic part only. This leads to interaction in the Gross–Pitaevskii approximation. Terms existing in the third order by the interaction radius are caused by the isotropic and nonisotropic parts of the interaction, and each of them introduces an interaction constant. Therefore, three interaction constants are involved in the model. Atoms, except for alkali and alkali-earth atoms, can have an anisotropic potential of interaction (this has particularly been demonstrated for the lanthanides). Short-wavelength instability caused by nonlocal terms appears in the Bogoliubov spectrum, and the conditions for stable and unstable behavior are described. Bright solitons in a repulsive Bose–Einstein condensate (BEC) are studied under the influence of anisotropic short-range interaction in the BEC of one species. The area of existence of bright solitons corresponds to the area of instability of the Bogoliubov spectrum. Approximate reduction of nonlocal nonlinearity to quintic nonlinearity in the bright soliton regime is also demonstrated.