- ID:
- ivo://CDS.VizieR/J/ApJ/855/49
- Title:
- ALMA astrochemical obs. of the merger NGC 3256
- Short Name:
- J/ApJ/855/49
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In external galaxies, molecular composition may be influenced by extreme environments such as starbursts and galaxy mergers. To study such molecular chemistry, we observed the luminous infrared galaxy and merger NGC 3256 using the Atacama Large Millimeter/submillimeter Array. We covered most of the 3 and 1.3mm bands for a multispecies, multitransition analysis. We first analyzed intensity ratio maps of selected lines such as HCN/HCO^+^, which shows no enhancement at an active galactic nucleus. We then compared the chemical compositions within NGC 3256 at the two nuclei, tidal arms, and positions with influence from galactic outflows. We found the largest variation in SiO and CH_3_OH, species that are likely to be enhanced by shocks. Next, we compared the chemical compositions in the nuclei of NGC 3256, NGC 253, and Arp 220; these galactic nuclei have varying star formation efficiencies. Arp 220 shows higher abundances of SiO and HC_3_N than NGC 3256 and NGC 253. Abundances of most species do not show a strong correlation with star formation efficiencies, although the CH_3_CCH abundance seems to have a weak positive correlation with the star formation efficiency. Lastly, the chemistry of spiral arm positions in NGC 3256 is compared with that of W51, a Galactic molecular cloud complex in a spiral arm. We found higher fractional abundances of shock tracers, and possibly also a higher dense gas fraction in NGC 3256 compared with W51.
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- ID:
- ivo://fai.kz/ssa/neutrons/q
- Title:
- Alma-Ata Station Neutron Monitor Data Service
- Short Name:
- neutrons data
- Date:
- 12 Dec 2024 16:35:27
- Publisher:
- Fesenkov Astrophysical Institute
- Description:
- The Alma-Ata Cosmic Ray Station operates the 18NM-64 neutron supermonitor at an altitude of 3340 meters above sea level with a geomagnetic cutoff rigidity of 6.7 GeV. The station provides real-time minute-level measurements of cosmic ray intensity and atmospheric pressure, contributing data to the international NMDB network (http://www.nmdb.eu). This service publishes daily tables containing two columns: - **timestamp**: Actual measurement times, ensuring accurate tracking. - **counts/sec**: Cosmic ray intensity in counts per second. The timestamps reflect actual measurement times, ensuring accurate tracking even when delayed data from previous days is incorporated into current files due to communication delays with space stations. The data is collected and provided by the Institute of Ionosphere (https://ionos.kz/).
- ID:
- ivo://CDS.VizieR/J/MNRAS/478/1512
- Title:
- ALMA calibrator continuum observations catalog
- Short Name:
- J/MNRAS/478/1512
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalogue of ALMA flux density measurements of 754 calibrators, obtained during the majority of the ALMA science observations between 2012 August and 2017 September, for a total of 16263 observations in different bands and epochs. The flux densities were measured by reprocessing the ALMA images generated in the framework of the ALMACAL project, with a new code developed by the Italian node of the European ALMA Regional Centre. A search in the online data bases yielded redshift measurements for 589 sources (about 78 per cent of the total). Almost all sources are flat spectrum, based on their low-frequency spectral index, and have properties consistent with being blazars of different types.
- ID:
- ivo://CDS.VizieR/J/ApJ/860/124
- Title:
- ALMA continuum emission obs. of MWC 758 disk
- Short Name:
- J/ApJ/860/124
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Spatially resolved structures in protoplanetary disks hint at unseen planets. Previous imaging observations of the transitional disk around MWC 758 revealed an inner cavity, a ring-like outer disk, emission clumps, and spiral arms, all possibly generated by companions. We present ALMA dust continuum observations of MWC 758 at 0.87mm wavelength with 43x39mas angular resolution (6.9x6.2au) and 20{mu}Jy/beam rms. The central submillimeter emission cavity is revealed to be eccentric; once deprojected, its outer edge can be well fitted by an ellipse with an eccentricity of 0.1 and one focus on the star. The broad ring-like outer disk is resolved into three narrow rings with two gaps in between. The outer two rings tentatively show the same eccentricity and orientation as the innermost ring bounding the inner cavity. The two previously known dust emission clumps are resolved in both the radial and azimuthal directions, with radial widths equal to ~4x the local scale height. Only one of the two spiral arms previously imaged in near-infrared (NIR) scattered light is revealed in ALMA dust emission, at a slightly larger stellocentric distance owing to projection effects. We also submit evidence of disk truncation at ~100au based on comparing NIR imaging observations with models. The spirals, the north clump, and the truncated disk edge are all broadly consistent with the presence of one companion exterior to the spirals at roughly 100au.
- ID:
- ivo://CDS.VizieR/J/A+A/626/A36
- Title:
- ALMA continuum fits files of G9.62+0.19
- Short Name:
- J/A+A/626/A36
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We used Band 7 ALMA observations in full polarisation mode to analyse the polarised dust emission of the massive star forming region G9.62+0.19. We estimated the magnetic field strength via the Davis-Chandrasekhar-Fermi and structure function methods. We resolve several protostellar cores embedded in a bright and dusty filamentary structure. The magnetic field is orientated along the filament and appears perpendicular to the direction of the outflows. The polarisation vectors present ordered patterns and the cores showing polarised emission are less fragmented. We suggest an evolutionary sequence of the magnetic field, and the less evolved hot core exhibits a stronger magnetic field than the more evolved hot core. An average magnetic field strength of the order of 11mG was derived, from which we obtain a low turbulent-to-magnetic energy ratio, indicating that turbulence does not significantly contribute to the stability of the clump. We report a detection of linear polarisation from thermal line emission, probably from methanol or carbon dioxide, and we tentatively compared linear polarisation vectors from our observations with previous linearly polarised OH masers observations.
- ID:
- ivo://CDS.VizieR/J/A+A/648/A33
- Title:
- ALMA continuum images of TW Hya
- Short Name:
- J/A+A/648/A33
- Date:
- 08 Feb 2022 14:06:34
- Publisher:
- CDS
- Description:
- A key piece of information to understand the origin and role of protoplanetary disk substructures is their dust content. In particular, disk substructures associated with gas pressure bumps can work as dust traps, accumulating grains and reaching the necessary conditions to trigger the streaming instability. In order to shed some light on the origin and role that disk substructures play in planet formation, we aim to characterize the dust content of substructures in the disk of TW Hya. We present Atacama Large Millimeter Array (ALMA) observations of TW Hya at 3.1mm with ~50 milliarcsecond resolution. These new data were combined with archival high angular resolution ALMA observations at 0.87mm, 1.3mm, and 2.1mm. We analyze these multiwavelength data to infer a disk radial profile of the dust surface density, maximum particle size, and slope of the particle size distribution. Most previously known annular substructures in the disk of TW Hya are resolved at the four wavelengths. Inside the inner 3au cavity, the 2.1mm and 3.1mm images show a compact source of free-free emission, likely associated with an ionized jet. Our multiwavelength analysis of the dust emission shows that the maximum particle size in the disk of TW Hya is >1mm. The inner 20au are completely optically thick at all four bands, which results in the data tracing different disk heights at different wavelengths. Coupled with the effects of dust settling, this prevents the derivation of accurate density and grain size estimates in these regions. At r>20au, we find evidence of the accumulation of large dust particles at the position of the bright rings, indicating that these are working as dust traps. The total dust mass in the disk is between 250 and 330M_{sun}_, which represents a gas-to-dust mass ratio between 50 and 70. Our mass measurement is a factor of 4.5-5.9 higher than the mass that one would estimate using the typical assumptions of large demographic surveys. Our results indicate that the ring substructures in TW Hya are ideal locations to trigger the streaming instability and form new generations of planetesimals.
- ID:
- ivo://CDS.VizieR/J/A+A/630/A59
- Title:
- ALMA continuum-subtracted datacubes for 48 QSOs
- Short Name:
- J/A+A/630/A59
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the stacking analysis of a sample of 48 quasi-stellar objects (QSOs) at 4.5<z<7.1 detected by the Atacama Large Millimetre Array (ALMA) in the [CII] {lambda}158um emission line to investigate the presence and the properties of massive, cold outflows associated with broad wings in the [CII] profile. The high sensitivity reached through this analysis allows us to reveal very broad [CII] wings tracing the presence of outflows with velocities in excess of 1000km/s. We find that the luminosity of the broad [CII] emission increases with LAGN, while it does not significantly depend on the star formation rate of the host galaxy, indicating that the central active galactic nucleus (AGN) is the main driving mechanism of the [CII] outflows in these powerful, distant QSOs. From the stack of the ALMA cubes, we derive an average outflow spatial extent of ~3.5kpc. The average atomic neutral mass outflow rate inferred from the stack of the whole sample is dM_out_/dt~100M_{sun}_/yr, while for the most luminous systems it increases to ~200M_{sun}_/yr. The associated outflow kinetic power is about 0.1% of L_AGN_, while the outflow momentum rate is ~L_AGN_/c or lower, suggesting that these outflows are either driven by radiation pressure onto dusty clouds or, alternatively, are driven by the nuclear wind and energy conserving but with low coupling with the interstellar medium. We discuss the implications of the resulting feedback effect on galaxy evolution in the early Universe.
- ID:
- ivo://CDS.VizieR/J/ApJ/774/73
- Title:
- ALMA CO observations of 30 Dor
- Short Name:
- J/ApJ/774/73
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Atacama Large (sub)Millimeter Array observations of 30 Doradus - the highest resolution view of molecular gas in an extragalactic star formation region to date (~0.4pcx0.6pc). The 30Dor-10 cloud north of R136 was mapped in ^12^CO 2-1, ^13^CO 2-1, C^18^O 2-1, 1.3mm continuum, the H30{alpha} recombination line, and two H_2_CO 3-2 transitions. Most ^12^CO emission is associated with small filaments and clumps (<~1pc, ~10^3^M_{sun}_ at the current resolution). Some clumps are associated with protostars, including "pillars of creation" photoablated by intense radiation from R136. Emission from molecular clouds is often analyzed by decomposition into approximately beam-sized clumps. Such clumps in 30 Doradus follow similar trends in size, linewidth, and surface density to Milky Way clumps. The 30 Doradus clumps have somewhat larger linewidths for a given size than predicted by Larson's scaling relation, consistent with pressure confinement. They extend to a higher surface density at a given size and linewidth compared to clouds studied at 10 pc resolution. These trends are also true of clumps in Galactic infrared-dark clouds; higher resolution observations of both environments are required. Consistency of clump masses calculated from dust continuum, CO, and the virial theorem reveals that the CO abundance in 30 Doradus clumps is not significantly different from the Large Magellanic Cloud mean, but the dust abundance may be reduced by ~2. There are no strong trends in clump properties with distance from R136; dense clumps are not strongly affected by the external radiation field, but there is a modest trend toward lower dense clump filling fraction deeper in the cloud.
- ID:
- ivo://CDS.VizieR/J/A+A/629/A30
- Title:
- ALMA CO observations of the system 4C12.50
- Short Name:
- J/A+A/629/A30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The nearby system 4C12.50, also known as IRAS 13451+1217 and PKS 1345+12, is a merger of gas-rich galaxies with infrared and radio activity. It has a perturbed interstellar medium (ISM) and a dense configuration of gas and dust around the nucleus. The radio emission at small (~100pc) and large (~100kpc) scales, as well as the large X-ray cavity in which the system is embedded, are indicative of a jet that could have affected the ISM. We carried out observations of the CO(1-0), (3-2), and (4-3) lines with the Atacama Large Millimeter Array (ALMA) to determine basic properties (i.e., extent, mass, and excitation) of the cold molecular gas in this system, including its already-known wind. The CO emission reveals the presence of gaseous streams related to the merger, which result in a small (4kpc-wide) disk around the western nucleus. The disk reaches a rotational velocity of 200km/s, and has a mass of 3.8(+/-0.4)10^9^M_{sun}_. It is truncated at a gaseous ridge north of the nucleus that is bright in [OIII]. Regions with high-velocity CO emission are seen at signal-to-noise ratios of between 3 and 5 along filaments that radially extend from the nucleus to the ridge and that are bright in [O iii] and stellar emission. A tentative wind detection is also reported in the nucleus and in the disk. The molecular gas speed could be as high as 2200km/s and the total wind mass could be as high as 1.5(+/-0.1)10^9^M_{sun}_. Energetically, it is possible that the jet, assisted by the radiation pressure of the active nucleus or the stars, accelerated clouds inside an expanding bubble.
- ID:
- ivo://CDS.VizieR/J/A+A/645/A97
- Title:
- ALMA cube and GMC catalog of J1023+1952
- Short Name:
- J/A+A/645/A97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Tidal dwarf galaxies (TDGs) are gravitationally bound condensations of gas and stars that formed during galaxy interactions. Here we present multi-configuration ALMA observations of J1023+1952, a TDG in the interacting system Arp 94, where we resolved CO(2-1) emission down to giant molecular clouds (GMCs) at 0.64" ~45pc resolution. We find a remarkably high fraction of extended molecular emission (~80-90%), which is filtered out by the interferometer and likely traces diffuse gas. We detect 111 GMCs that give a similar mass spectrum as those in the Milky Way and other nearby galaxies (a truncated power law with a slope of -1.76+/-0.13). We also study Larson's laws over the available dynamic range of GMC properties (~2dex in mass and ~1dex in size): GMCs follow the size-mass relation of the Milky Way, but their velocity dispersion is higher such that the size-linewidth and virial relations appear super-linear, deviating from the canonical values. The global molecular-to-atomic gas ratio is very high (~1) while the CO(2-1)/CO(1-0) ratio is quite low (~0.5), and both quantities vary from north to south. Star formation predominantly takes place in the south of the TDG, where we observe projected offsets between GMCs and young stellar clusters ranging from ~50pc to ~200pc; the largest offsets correspond to the oldest knots, as seen in other galaxies. In the quiescent north, we find more molecular clouds and a higher molecular-to-atomic gas ratio (~1.5); atomic and diffuse molecular gas also have a higher velocity dispersion there. Overall, the organisation of the molecular interstellar medium in this TDG is quite different from other types of galaxies on large scales, but the properties of GMCs seem fairly similar, pointing to near universality of the star-formation process on small scales.
