- ID:
- ivo://CDS.VizieR/J/A+A/472/121
- Title:
- AMIGA V. Isolation parameters
- Short Name:
- J/A+A/472/121
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The AMIGA project aims to build a well defined and statistically significant reference sample of isolated galaxies in order to estimate the environmental effects on the formation and evolution of galaxies. The goal of this paper is to provide a measure of the environment of the isolated galaxies in the AMIGA sample, quantifying the influence of the candidate neighbours identified in our previous work and their potential effects on the evolution of the primary galaxies. Here we provide a quantification of the isolation degree of the galaxies in this sample.
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- ID:
- ivo://CDS.VizieR/J/A+A/609/A17
- Title:
- AMIGA XIII. HI properties
- Short Name:
- J/A+A/609/A17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the largest catalogue of HI single dish observations of isolated galaxies to date, as part of the multi-wavelength compilation being performed by the AMIGA project (Analysis of the interstellar Medium in Isolated GAlaxies). Despite numerous studies of the HI content of galaxies, no revision has been made for the most isolated L* galaxies since Haynes & Giovanelli (1984AJ.....89..758H). The AMIGA sample has been demonstrated to be almost "nurture free", therefore, by creating scaling relations for the HI content of these galaxies we will define a metric of HI normalcy in the absence of interactions. The catalogue comprises of our own HI observations with Arecibo, Effelsberg, Nancay and GBT, and spectra collected from the literature. In total we have measurements or constraints on the HI masses of 844 galaxies from the Catalogue of Isolated Galaxies (CIG). The multi-wavelength AMIGA dataset includes a revision of the B-band luminosities, optical diameters, morphologies, and isolation. Due to the large size of the catalogue, these revisions permit cuts to be made to ensure isolation and a high level of completeness, which was not previously possible. With this refined dataset we fit HI scaling relations based on luminosity, optical diameter and morphology. Our regression model incorporates all the data, including upper limits, and accounts for uncertainties in both variables, as well as distance uncertainties. The HI scaling relations of the AMIGA sample define an up-to-date metric of the HI content of almost "nurture free" galaxies. These relations allow the expected HI mass, in the absence of interactions, of an individual galaxy to be predicted to within 0.25dex (for typical measurement uncertainties). These relations are thus suitable for use as statistical measures of the impact of interactions on the neutral gas content of galaxies.
- ID:
- ivo://CDS.VizieR/J/A+A/545/A15
- Title:
- AMIGA XI. Optical nuclear activity
- Short Name:
- J/A+A/545/A15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This study was performe within the frame of the AMIGA project (http://amiga.iaa.es/). We obtained spectral data from the 6th Data Release of the Sloan Digital Sky Survey, which were inspected in a semi-automatic way. We subtracted the underlying stellar populations from the spectra (using the software Starlight) and modelled the nuclear emission features. Standard emission-line diagnostics diagrams were applied, using a new classification scheme that takes into account censored data, to classify the type of nuclear emission. We provide a final catalogue of spectroscopic data, stellar populations, emission lines and classification of optical nuclear activity for AMIGA galaxies. The prevalence of optical active galactic nuclei (AGN) in AMIGA galaxies is 20.4%, or 36.7% including transition objects. The fraction of AGN increases steeply towards earlier morphological types and higher luminosities. We compare these results with a matched analysis of galaxies in isolated denser environments (Hickson Compact Groups). After correcting for the effects of the morphology and luminosity, we find that there is no evidence for a difference in the prevalence of AGN between isolated and compact group galaxies, and we discuss the implications of this result. We find that a major interaction is not a necessary condition for the triggering of optical AGN.
- ID:
- ivo://CDS.VizieR/J/A+A/540/A47
- Title:
- AMIGA X. Isolated galaxy colors
- Short Name:
- J/A+A/540/A47
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The basic properties of galaxies can be affected by both nature (internal processes) or nurture (interactions and effects of environment). Deconvolving the two effects is an important current effort in astrophysics. Observed properties of a sample of isolated galaxies should be mainly the result of internal (natural) evolution. It follows that nurture-induced galaxy evolution can only be understood through a comparative study of galaxies in different environments. We take a first look at SDSS (g-r) colors of galaxies in the AMIGA sample, which consists of many of the most isolated galaxies in the local Universe. This alerted us at the same time the pitfalls of using automated SDSS colors.
- ID:
- ivo://CDS.VizieR/J/MNRAS/473/1512
- Title:
- AMI 15.7GHz GRB catalogue
- Short Name:
- J/MNRAS/473/1512
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the Arcminute Microkelvin Imager (AMI) Large Array catalogue of 139 gamma-ray bursts (GRBs). AMI observes at a central frequency of 15.7GHz and is equipped with a fully automated rapid-response mode, which enables the telescope to respond to high-energy transients detected by Swift. On receiving a transient alert, AMI can be on-target within 2-min, scheduling later start times if the source is below the horizon. Further AMI observations are manually scheduled for several days following the trigger. The AMI GRB programme probes the early-time (<1d) radio properties of GRBs, and has obtained some of the earliest radio detections (GRB 130427A at 0.36 and GRB 130907A at 0.51d post-burst). As all Swift GRBs visible to AMI are observed, this catalogue provides the first representative sample of GRB radio properties, unbiased by multiwavelength selection criteria. We report the detection of six GRB radio afterglows that were not previously detected by other radio telescopes, increasing the rate of radio detections by 50 per cent over an 18-month period. The AMI catalogue implies a Swift GRB radio detection rate of >~15 per cent, down to ~0.2mJy/beam. However, scaling this by the fraction of GRBs AMI would have detected in the Chandra & Frail (2012, Cat. J/ApJ/746/156) sample (all radio-observed GRBs between 1997 and 2011), it is possible ~44-56 per cent of Swift GRBs are radio bright, down to ~0.1-0.15mJy/beam. This increase from the Chandra & Frail (2012, Cat. J/ApJ/746/156) rate (~30 per cent) is likely due to the AMI rapid-response mode, which allows observations to begin while the reverse-shock is contributing to the radio afterglow.
- ID:
- ivo://CDS.VizieR/J/MNRAS/415/893
- Title:
- AMI-LA 16 GHz sources in Perseus region
- Short Name:
- J/MNRAS/415/893
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep radio continuum observations of the cores identified as deeply embedded young stellar objects in the Perseus molecular cloud by the Spitzer c2d programme at a wavelength of 1.8cm with the Arcminute Microkelvin Imager Large Array (AMI-LA). We detect 72% of Class 0 objects from this sample and 31% of Class I objects. No starless cores are detected. We use the flux densities measured from these data to improve constraints on the correlations between radio luminosity and bolometric luminosity, infrared luminosity and, where measured, outflow force. We discuss the differing behaviour of these objects as a function of protostellar class and investigate the differences in radio emission as a function of core mass. Two of four possible very low luminosity objects (VeLLOs) are detected at 1.8cm.
- ID:
- ivo://CDS.VizieR/J/ApJS/209/23
- Title:
- Aminoacetonitrile transition frequencies
- Short Name:
- J/ApJS/209/23
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Aminoacetonitrile, NH_2-CH_2_-CN, has been considered one of the important precursors of glycine, the simplest amino acid, and was identified in Sgr B2(N) by Belloche et al. (2008, Cat. J/A+A/482/179) based on their reanalysis of previous laboratory measurements. However, these laboratory measurements were limited to the 1mm wavelength region even for the normal species, and recent new radio telescopes like ALMA require rest frequencies in a higher frequency range. Therefore, we have extended the pure rotational spectra of aminoacetonitrile and its amino-hydrogen-deuterated isotopologues (NHDCH_2_CN and ND_2_CH_2_CN) up to 1.2THz and 0.6THz, respectively. Belloche et al. indicated that the normal species may have been misassigned in a previous microwave study by Bogey et al. (1990JMoSp.143..180B). We found that two more b-type spectral transitions were misassigned, and all b-type transition frequencies above K_a_=2 had to be remeasured. For isotopologues, spectra above 40 GHz were observed for the first time and higher order centrifugal distortion constants have been determined. The extension of the measurements helped improve the molecular constants. The errors in the frequency catalog data of normal and deuterated isotopologues are on the order of 100kHz up to 1.2THz and 0.6THz, respectively, which are precise enough for the future astronomical observations.
- ID:
- ivo://CDS.VizieR/J/ApJ/756/60
- Title:
- A 3mm line survey in 37 IR dark clouds
- Short Name:
- J/ApJ/756/60
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have observed 37 Infrared Dark Clouds (IRDCs), containing a total of 159 clumps, in high-density molecular tracers at 3mm using the 22m ATNF Mopra Telescope located in Australia. After determining kinematic distances, we eliminated clumps that are not located in IRDCs and clumps with a separation between them of less than one Mopra beam. Our final sample consists of 92 IRDC clumps. The most commonly detected molecular lines are (detection rates higher than 8%) N_2_H^+^, HNC, HN^13^C, HCO^+^, H^13^CO^+^, HCN, C_2_H, HC_3_N, HNCO, and SiO. We investigate the behavior of the different molecular tracers and look for chemical variations as a function of an evolutionary sequence based on Spitzer IRAC and MIPS emission. Optical depth calculations show that in IRDC clumps the N_2_H^+^ line is optically thin, the C_2_ H line is moderately optically thick, and HNC and HCO^+^ are optically thick.
- ID:
- ivo://CDS.VizieR/J/A+A/549/A39
- Title:
- A 3mm molecular line survey of NGC1068
- Short Name:
- J/A+A/549/A39
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the molecular composition of the interstellar medium (ISM) surrounding an active galactic nucleus (AGN), by making an inventory of molecular species and their abundances, to establish a chemical differentiation between starburst galaxies and AGN. We used the IRAM-30m telescope to observe the central 1.5-2kpc region of NGC 1068, covering the frequencies between 86.2GHz and 115.6GHz. Using Boltzmann diagrams, we calculated the column densities of the detected molecules. We used a chemical model to reproduce the abundances found in the AGN, to determine the origin of each detected species, and to test the influence of UV fields, cosmic rays, and shocks on the ISM.
- ID:
- ivo://CDS.VizieR/J/AJ/152/92
- Title:
- Ammonia and CO outflow around 6.7GHz methanol masers
- Short Name:
- J/AJ/152/92
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Single point observations are presented in NH_3_ (1, 1) and (2, 2) inversion transitions using the Effelsberg 100m telescope for a sample of 100 6.7GHz methanol masers and mapping observations in the ^12^CO and ^13^CO (1-0) transitions using the Purple Mountain Observatory Delingha 13.7m telescope for 82 sample sources with detected ammonia. A further 62 sources were selected for either ^12^CO or ^13^CO line outflow identification, producing 45 outflow candidates, 29 using ^12^CO and 16 using ^13^CO data. Twenty-two of the outflow candidates were newly identified, and 23 had trigonometric parallax distances. Physical properties were derived from ammonia lines and CO outflow parameters were calculated. Histograms and statistical correlations for ammonia, CO outflow parameters, and 6.7GHz methanol maser luminosities are also presented. No significant correlation was found between ammonia and maser luminosity. However, weak correlations were found between outflow properties and maser luminosities, which may indicate that outflows are physically associated with 6.7GHz masers.
