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We explore large-scale cosmic structure using the spatial distribution of 542 gamma-ray bursts (GRBs) having accurately measured positions and spectroscopic redshifts. Prominent cosmological clusters are identified in both the northern and southern galactic hemispheres (avoiding extinction effects in the plane of the Milky Way) using the bootstrap point-radius method. The northern galactic hemisphere contains a significant group of four GRBs in the redshift range 0.59 ≤ z ≤ 0.62 (with a bootstrap probability of p  = 0.012) along with the previously identified Hercules–Corona Borealis Great Wall (in the revised redshift range 0.9 ≤ z ≤ 2.1; p  = 0.017). The southern galactic hemisphere contains the previously identified Giant GRB Ring (p  = 0.022) along with another possible cluster of seven to nine GRBs at 1.17 ≤ z ≤ 1.444 (p  = 0.031). Additionally, both the Hercules–Corona Borealis Great Wall and the Giant GRB Ring have become more prominent as the GRB sample size has grown. The approach used here underscores the potential value of GRB clustering as a probe of large-scale cosmic structure, complementary to galaxy and quasar clustering. Because of the vast scale on which GRB clustering provides valuable insights, it is important that optical GRB monitoring continues so that additional spectroscopic redshift measurements could be obtained. [ABSTRACT FROM AUTHOR]

We processed the catalogue data for all snapshots of the Illustris TNG100 cosmological simulation and collected every calculated property of the galaxies formed at different redshifts. With this dataset we can statistically analyze parameters for galaxy samples at given redshifts, as well as trace sample parameters over the entire time range of the simulation. Focusing first on star formation rate (SFR) and metallicity, we see the cosmic star formation history with the mean maximum at around z ≈ 1.6 and the reionization bump at around z ≈ 5, while metallicity increases. For a sample of strongly star-forming galaxies with SFR > 10 M⊙ yr−1 we found different characteristics compared to the whole sample. The mean metallicity of highly star-forming galaxies is higher and changes less, and the mean SFR has its maximum at around the reionization bump. [ABSTRACT FROM AUTHOR]

This work aims to represent the physical properties of a sample of infrared-bright dust-obscured galaxies (DOGs) studied by Suleiman et al. (2022) by fitting the spectral energy distributions (SEDs). Twenty-eight DOGs were examined at redshifts 0.47 ≤ z ≤ 1.63 discovered by combining images of the Subaru Hyper Suprime-Cam (HSC) survey, VISTA Kilo-degree Infrared Galaxy (VIKING) survey, and the Wide-field Infrared Survey Explorer (WISE) all-sky survey, and detected at Herschel Spectral and Photometric Imaging Receiver (SPIRE) bands. The results show a correlation between the star formation rate (SFR) and the dust luminosity of Suleiman et al. (2022) DOG sample, the SFR ranges of the sample according to different redshifts, and a comparison between Suleiman et al. (2022) sample and other samples of DOGs. [ABSTRACT FROM AUTHOR]

The aim of this study is to characterize the physical and statistical properties of a sample of infrared-bright dust-obscured galaxies (DOGs) by fitting their spectral energy distributions (SEDs). We examined 28 DOGs at redshifts 0.47 ≤ z ≤ 1.63 discovered by combining images of the Subaru Hyper Suprime-Cam (HSC) survey, the VISTA Kilo-degree Infrared Galaxy (VIKING) survey, and the Wide-field Infrared Survey Explorer (WISE) all-sky survey, and detected at Herschel Spectral and Photometric Imaging Receiver (SPIRE) bands. We have detected a significant active galactic nucleus (AGN) contribution to the mid-infrared luminosity for |$71\%$| of DOGs. Our DOGs contain several types of AGNs; the majority of AGN emission originates from Type 2 AGNs. Our DOG sample shows very high values of stellar mass [log (M */ M |${}_\odot $|⁠) = 11.49 ± 1.61] compared with other samples of DOGs selected at infrared wavelengths. Our study is promising to identify a new type of DOGs called "overweight" DOGs (ODOGs). ODOGs may indicate the end of the DOG phase, and then they become visible quasars. Principal component (PC) analysis is applied to reduce the number of dimensions of our sample, removing the dependency on the observed variables. There are two significant PCs describing |$72.7\%$| of the total variance. The first PC strongly correlates with redshift, dust luminosity, dust mass, and stellar mass, while far-ultraviolet (FUV) attenuation strongly correlates with the second PC, which is orthogonal to the first one. The partial correlation between the resulted physical parameters is tested, supporting the reliability of the correlations. [ABSTRACT FROM AUTHOR]

Gamma-ray bursts (GRBs) are the most luminous objects known: they outshine their host galaxies, making them ideal candidates for probing large-scale structure. Our aim is to determine the Spatial Two-Point Correlation Function of the GRBs with spectroscopic redshifts. We used all observations till 4 June 2021, and we also split the data according to the origin of the redshift (afterglow or host galaxy). We analyzed the possible correlation between the GRB redshift and sky position. There is only one region, called the Faraway GRB Patch, where nine distant GRBs shows deviation from the randomness with an ≈1% significance, showing that the sky and the radial component of the GRB distribution could be factorized and both can be determined independently. The GRBs' cumulative monthly distribution was used to show that it is impossible to synthesize the Sky Exposure Function, even from the perfect observational logs. We estimated the Sky Exposure Function using the Gaussian kernel, and with the radial distribution, it was used for the estimation of the Spatial Two-Point Correlation Function. Monte Carlo simulations were used to determine the Poissonian errors. Our result shows that the current Spatial Two-Point Correlation Function estimations are consistent with zero for the full and the afterglow/host galaxy datasets. [ABSTRACT FROM AUTHOR]

To understand the nature of SiO emission, we conducted ACA observations of the SiO (2-1) lines toward 146 massive star-forming regions, as part of the ALMA Three-millimeter Observations of Massive Star-forming regions (ATOMS) survey. We detected SiO emission in 128 (87.7 |${{\ \rm per\ cent}}$|⁠) sources and identified 171 SiO clumps, 105 of which are spatially separated from 3 mm continuum emission. A large amount of the SiO line profiles (60 |${{\ \rm per\ cent}}$|⁠) are non-Gaussian. The velocity dispersion of the SiO lines ranges from 0.3 to 5.43 km s−1. In 63 sources the SiO clumps are associated with H  ii regions characterized by H40α emission. We find that 68 |${{\ \rm per\ cent}}$| (116) of the SiO clumps are associated with strong outflows. The median velocity dispersion of the SiO line for outflow sources and non-outflow sources is 1.91 km s−1 and 0.99 km s−1, respectively. These results indicate that outflow activities could be connected to strongly shocked gas. The velocity dispersion and [SiO]/[H13CO+] intensity ratio do not show any correlation with the dust temperature and particle number density of clumps. We find a positive correlation between the SiO line luminosity and the bolometric luminosity, implying stronger shock activities are associated with more luminous protoclusters. The SiO clumps in associations with H  ii regions were found to show a steeper feature in |$L_{\rm{sio}}$| / |$L_{\rm{bol}}$|⁠. The SiO line luminosity and the fraction of shocked gas have no apparent evidence of correlation with the evolutionary stages traced by luminosity to mass ratio (⁠|$L_{\rm{bol}}/M$|⁠). [ABSTRACT FROM AUTHOR]

We applied image stacking on empty field Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) survey maps centred on optically identified high-redshift quasars at |$z\ge 4$| to uncover the hidden |$\mu$| Jy radio emission in these active galactic nuclei (AGN). The median stacking procedure for the full sample of 2229 optically identified AGN uncovered an unresolved point source with an integrated flux density of 52  |$\mu$| Jy, with a signal-to-noise ratio |${\sim} 10$|⁠. We co-added the individual image centre pixels to estimate the characteristic monochromatic radio power at 1.4 GHz considering various values for the radio spectral index, revealing a radio population with |$P_\mathrm{1.4\, GHz}\sim 10^{24}$|  W Hz |$^{-1}$|⁠. Assuming that the entire radio emission originates from star-forming (SF) activity in the nuclear region of the host galaxy, we obtained an upper limit on the characteristic star formation rate, |${\sim} 4200$|  M |$_\odot$|  yr |$^{-1}$|⁠. The angular resolution of FIRST images is insufficient to distinguish between the SF and AGN origin of radio emission at these redshifts. However, a comparison with properties of individual sources from the literature indicates that a mixed nature is likely. Future very long baseline interferometry radio observations and ultradeep Square Kilometre Array surveys are expected to be sensitive enough to detect and resolve the central |$1\!-\!10$|  kpc region in the host galaxies, and thus discriminate between SF and AGN related emission. [ABSTRACT FROM AUTHOR]

The new, small satellite‐based gamma‐ray detectors, like Cubesats Applied for MEasuring and Localizing Transients, will provide a new way to detect gamma transients in the multimessenger era. The efficiency and the detection capabilities of such a system will be compared with current missions, for example, Fermi Gamma‐ray Burst Monitor (GBM). We used the Fermi GBM's observed short gamma‐ray burst light curves aggregated from observed discrete detector event for the simulation input. The corresponding direction‐dependent detector response matrices were used to generate photon counts and light curves around a simulated event, enabling to determine the statistics. This method can be used in the future for trigger algorithm and detector system development, and also to estimate the efficiency of the data analysis pipeline regarding the observable gamma‐ray bursts' parameters as well as other electromagnetic transients. [ABSTRACT FROM AUTHOR]

The present-day Earth with its innumerable life forms is a product of cosmic evolution starting with the formation of our galaxy and the dense gas clouds within it, and proceeding through the contraction of one of those clouds about 4.6 Gyr ago, first into filaments and then one or more protostellar disks, planets, and central stars, one of which was our Sun. Radioactive debris from a massive nearby star was included. The planets themselves formed through coagulation, accretion, and fragmentation of solid bodies. Habitability depends on a delicate balance between disk accretion by gravity and dispersal by the central star, which determine the size of the planet and its gaseous envelope, combined with a long period of stellar radiation, which has to disperse this envelope but leave a hospitable secondary atmosphere. The final step toward life involves even more complexity as self-replicating bio-molecules form with ever increasing stability. [ABSTRACT FROM AUTHOR]

We estimated several parameters of dwarf galaxies, including their star formation rate and dust mass, and compared them with galaxies with larger stellar masses. We have chosen dwarf galaxies in the ELAIS N1 field, and fitted their Spectral Energy Distributions (SED). We used data from the new Herschel SPIRE and PACS Point Source catalogues to constrain the infrared radiation. Data available in VIZIER from multiple surveys have also been used. We determined that the star formation rate (SFR), M* and M dust is one order of magnitude lower in dwarf galaxies compared to galaxies with larger stellar masses. However, the starburtiness was higher in the dwarf galaxies. They also had lower redshifts than normal galaxies, so we compared them to a subsample of normal galaxies with lower redshifts. The dust masses and SFRs of the dwarf galaxies were slightly lower, but their starburtiness was higher. [ABSTRACT FROM AUTHOR]

Statistical studies of gamma-ray burst (GRB) spectra may result in important information on the physics of GRBs. The Fermi GBM catalogue contains GRB parameters (peak energy, spectral indices, and intensity) estimated fitting the gamma-ray spectral energy distribution of the total emission (fluence, flnc), and during the time of the peak flux (pflx). Using contingency tables, we studied the relationship of the models best-fitting pflx and flnc time intervals. Our analysis revealed an ordering of the spectra into a power law- Comptonized - smoothly broken power law - Band series. This result was further supported by a correspondence analysis of the pflx and flnc spectra categorical variables. We performed a linear discriminant analysis (LDA) to find a relationship between categorical (spectral) and model independent physical data. LDA resulted in highly significant physical differences among the spectral types, that is more pronounced in the case of the pflx spectra, than for the flnc spectra. We interpreted this difference as caused by the temporal variation of the spectrum during the outburst. This spectral variability is confirmed by the differences in the low-energy spectral index and peak energy, between the pflx and flnc spectra.We found that the synchrotron radiation is significant inGBM spectra. The mean low-energy spectral index is close to the canonical value of α = -2/3 during the peak flux. However, α is ∼-0.9 for the spectra of the fluences. We interpret this difference as showing that the effect of cooling is important only for the fluence spectra. [ABSTRACT FROM AUTHOR]

We demonstrate the use of the AKARI all-sky survey photometric data in the study of galactic star formation. Our aim was to select young stellar objects (YSOs) in the AKARI Far-Infrared Surveyor (FIS) Bright Source Catalogue. We used AKARI/FIS and Wide-field Infrared Survey Explorer (WISE) data to derive mid- and far-infrared colors of YSOs. Classification schemes based on quadratic discriminant analysis (QDA) have been given for YSOs and the training catalog for QDA was the whole-sky selection of previously known YSOs (i.e., listed in the SIMBAD database). A new catalog of AKARI FIS YSO candidates including 44001 sources has been prepared; the reliability of the classification is over 90%, as tested in comparison to known YSOs. As much as 76% of our YSO candidates are from previously uncatalogued types. The vast majority of these sources are Class I and II types according to the Lada classification. The distribution of AKARI FIS YSOs is well correlated with that of the galactic ISM; local over-densities were found on infrared loops and towards the cold clumps detected by Planck. [ABSTRACT FROM AUTHOR]

Division VI provides a focus for astronomers studying a wide range of problems related to the physical and chemical properties of interstellar matter in the Milky Way and other galaxies. [ABSTRACT FROM PUBLISHER]

Our goal is to evaluate the role of triggering effects on the star formation and early stellar evolution by presenting a statistically large sample of cloud and low-mass YSO data. We conducted large area surveys (ranging from 400 square-degree to 10800 square-degree) in optical, NIR and FIR. The distribution of the ISM and low-mass YSOs were surveyed. A relative excess was found statistically in the number of dense and cold core bearing clouds and low mass YSOs in the direction of the FIR loop shells indicating a possible excess in their formation. [ABSTRACT FROM PUBLISHER]

Recently a large number of Galactic cold clumps were located with the Planck all-sky survey. Our radio line observations have revealed the distribution and physical properties of the interstellar medium in dozens of PGCC sources. Clumps can be affected by many external effects. HCL1 (a.k.a. L1251) and HCL2 (which contains also TMC-1) are examples of low mass star forming clouds in violent and quiet environments. [ABSTRACT FROM AUTHOR]

The fragmentation of interstellar molecular clouds has been investigated with great effort by many authors. In this paper, a simple model is given to describe the dynamics of two fragments moving in a special cylindrical potential. Using a modified version of the restricted three-body problem and the corresponding Jacobian integral, some constraints are given for the motion of the fragments. [ABSTRACT FROM AUTHOR]

We studied the space distribution of the starburst galaxies from Millennium XXL database at z = 0.82. We examined the starburst distribution in the classical Millennium I (De Lucia et al. (2006)) using a semi-analytical model for the genesis of the galaxies. We simulated a starburst galaxies sample with Markov Chain Monte Carlo method. The connection between the large scale structures homogenous and starburst groups distribution (Kofman and Shandarin 1998), Suhhonenko et al. (2011), Liivamägi et al. (2012), Park et al. (2012), Horvath et al. (2014), Horvath et al. (2015)) on a defined scale were checked too. [ABSTRACT FROM PUBLISHER]

Gamma-ray bursts are the most luminous objects known: they outshine their host galaxies making them ideal candidates for probing large-scale structure. Earlier it has been found that the angular distribution of different groups of GRBs (long, intermediate and short) show deviation from the full randomness at different levels (e.g. Vavrek et al. (2008)).In the current sample there are more than 361 GRBs with position and redshift: the large scale homogeneous and isotropic distribution were checked with nearest-neighbour tests and with the two-point correlation function. [ABSTRACT FROM PUBLISHER]

Galactic cold clumps have been identified from the Planck data (Planck Collaboration, 2011a, 2011b, 2015) as 10 342 cold (7 - 19 K) sources that stand out against a warmer environment, with the Early Cold Cores as a subsample of 915 most reliable detections. There is CO emission associated with the Planck Cold Clumps (PCCs), which has been observed with ground-based radio telescopes at higher resolution (Wu et al. 2012, Liu et al. 2014). A subset of PCCs have also been observed with Herschel at higher resolution (Juvela et al. 2012).A southern sub-sample of the PCCs has been observed with the Mopra 22-m telescope to study the molecular gas. The Mopra telescope has 3-mm, 7-mm and 12-mm bands, with broadband correlator configuration 8-GHz wide with 0.27-MHz channels, or multiple zoom bands 137-MHz wide with 33-KHz channels, within the 8 GHz.During the 2013 southern winter season we observed 10 clumps. This included observations in the 3-mm band of 12CO, 13CO and C18O and lines around 89 GHz (e.g. HCN, HCO+ and HNC), in the 7-mm band (e.g. CS) and in the 12-mm band (e.g. NH3). These observations were heterogenous, with sources selected by LST in gaps between observations of other projects, and band chosen by weather (i.e. in conditions unsuitable for higher frequencies, lower frequency bands were observed). During the 2014 season we observed 34 positions in 22 clumps, with zoom mode observations of lines around 89 GHz. This was a more well-defined sample of sources.The mapping of the CO lines shows good spatial correlation of the CO with the dust column density The CO isotoplogues show high optical depth in 12CO and 13CO. The lines of HCN, HCO+ and HNC are weak, but detected in many of the 2014 sample. We are modelling the line results to determine column densities, excitation temperatures and abundances, using tools such as radex (van der Tak et al. 2007). [ABSTRACT FROM PUBLISHER]

We revealed a statistically significant clustering in the all sky distribution of AKARI-WISE young stellar objects with large groups of elongated and bush types. [ABSTRACT FROM PUBLISHER]

Physical parameters were derived for 100 young stellar objects in the TAPO region. [ABSTRACT FROM PUBLISHER]