- ID:
- ivo://CDS.VizieR/J/ApJ/872/202
- Title:
- CFHT ugi photometry of globular clusters in M85
- Short Name:
- J/ApJ/872/202
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We survey globular clusters (GCs) in M85 using ugi-band images of a 1{deg}x1{deg} field obtained with the MegaCam at the 3.6m Canada-France-Hawaii Telescope. We identify 1318 GC candidates with 20.0mag<g_0_<23.5mag in the entire survey region. Their radial number density profile is well fit by a Sersic profile with n=2.58_-0.33_^+0.43^ and effective radius R_e,GCS_=4.14' (=22kpc), showing that the candidates at R<20' are mostly genuine GCs in M85. We estimate the total number of GCs, N(total)=1216_-50_^+82^, and the specific frequency, S_N_=1.41_-0.06_^+0.10^. The overall color distribution of the GCs in M85 is bimodal, but the GCs in the central region at R<2' do not show a bimodal distribution clearly. The radial number density profile and surface number density map of the blue GCs (BGCs) show more extended structures than those of the red GCs (RGCs). The spatial distributions of both BGCs and RGCs are elongated, similar to that of the galaxy stellar light. The number fraction of the RGCs in the central region is much smaller compared to those in other early-type galaxies of similar luminosity. The mean (g-i)_0_ color of the RGCs in M85 is about 0.1mag bluer than typical values for other Virgo early-type galaxies of similar luminosity, indicating that a significant fraction of the RGCs in M85 may be younger than typical GCs. These results indicate that M85 might have undergone a major wet merger recently.
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- ID:
- ivo://CDS.VizieR/J/ApJS/109/367
- Title:
- 4C 23.56 field deep imaging
- Short Name:
- J/ApJS/109/367
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep infrared and optical imaging of a 1.25arcmin^2^ field centered on the giant (~0.5Mpc) high-redshift (z=2.479) ultra-steep-spectrum radio source 4C 23.56. The optical/infrared continuum morphology of the host galaxy is asymmetric, with strong color gradients and an enormous biconical emission-line nebula. The morphology of 4C 23.56 is best described by a dusty galaxy illuminated by a beam from an active galactic nucleus that is scattered into our line of sight. We determine the K' band number counts in the field to a limit of K'=22.5mag and find a marginally significant excess of objects with K'=19-21mag, compared to other K' band surveys. Spectral energy distributions (SEDs) of 117 objects in the field are constructed from aperture photometry in five bands (U', NB, V, I, and K'). From the SEDS we distinguish three subsets of objects as possible candidates for z~2.48 companions: emission-line galaxies, very red galaxies, and flat-spectrum star-forming galaxies. The field has nine candidate objects with line emission in a narrow band centered on the redshifted Ly{alpha} line, compared to an expected number of at most three foreground [O II] emitters that could mimic Ly{alpha} alpha sources. We find a high density of faint, very red objects with I-K'>4mag in the field, including two with I-K'>6mag.
- ID:
- ivo://CDS.VizieR/J/A+A/566/L5
- Title:
- C/2012 F6 (Lemmon) and C/2013 R1 (Lovejoy) spectra
- Short Name:
- J/A+A/566/L5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A spectral survey in the 1mm wavelength range was undertaken in the long-period comets C/2012 F6 (Lemmon) and C/2013 R1 (Lovejoy) using the 30m telescope of the Institut de radioastronomie millimetrique (IRAM) in April and November-December 2013. We report the detection of ethylene glycol (CH_2OH)_2 (aGg' conformer) and formamide (NH_2CHO) in the two comets. The abundances relative to water of ethylene glycol and formamide are 0.2-0.3% and 0.02% in the two comets, similar to the values measured in comet C/1995 O1 (Hale-Bopp). We also report the detection of HCOOH and CH_3_CHO in comet C/2013 R1 (Lovejoy), and a search for other complex species (methyl formate, glycolaldehyde).
- ID:
- ivo://CDS.VizieR/J/A+A/589/A78
- Title:
- C/2012 F6 (Lemmon) and C/2013 R1 spectra (Lovejoy)
- Short Name:
- J/A+A/589/A78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The apparition of bright comets C/2012 F6 (Lemmon) and C/2014 Q2 (Lovejoy) in March-April 2013 and January 2015, combined with the improved observational capabilities of submillimeter facilities, offered an opportunity to carry out sensitive compositional and isotopic studies of the volatiles in their coma. We observed comet Lovejoy with the IRAM 30m telescope between 13 and 26 January 2015, and with the Odin submillimeter space observatory on 29 January - 3 February 2015. We detected 22 molecules and several isotopologues. The H216O and H218O production rates measured with Odin follow a periodic pattern with a period of 0.94 days and an amplitude of ~25%. The inferred isotope ratios in comet Lovejoy are ^16^O/^18^O=499+/-24 and D/H=1.4+/-0.4*10^-4^ in water, ^32^S/^34^S=24.7+/-3.5 in CS, all compatible with terrestrial values. The ratio ^12^C/^13^C=109+/-14 in HCN is marginally higher than terrestrial and ^14^N/^15^N=145+/-12 in HCN is half the Earth ratio. Several upper limits for D/H or ^12^C/^13^C in other molecules are reported. From our observation of HDO in comet C/2014 Q2 (Lovejoy), we report the first D/H ratio in an Oort Cloud comet that is not larger than the terrestrial value. On the other hand, the observation of the same HDO line in the other Oort-cloud comet, C/2012 F6 (Lemmon), suggests a D/H value four times higher. Given the previous measurements of D/H in cometary water, this illustrates that a diversity in the D/H ratio and in the chemical composition, is present even within the same dynamical group of comets, suggesting that current dynamical groups contain comets formed at very different places or times in the early solar system.
- ID:
- ivo://CDS.VizieR/J/ApJ/792/L2
- Title:
- C/2012 F6 (Lemmon) and C/2012 S1 (ISON) maps
- Short Name:
- J/ApJ/792/L2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Results are presented from the first cometary observations using the Atacama Large Millimeter/Submillimeter Array (ALMA), including measurements of the spatially resolved distributions of HCN, HNC, H_2_CO, and dust within the comae of two comets: C/2012 F6 (Lemmon) and C/2012 S1 (ISON), observed at heliocentric distances of 1.5 AU and 0.54 AU, respectively. These observations (with angular resolution ~0.5"), reveal an unprecedented level of detail in the distributions of these fundamental cometary molecules, and demonstrate the power of ALMA for quantitative measurements of the distributions of molecules and dust in the inner comae of typical bright comets. In both comets, HCN is found to originate from (or within a few hundred kilometers of) the nucleus, with a spatial distribution largely consistent with spherically symmetric, uniform outflow. By contrast, the HNC distributions are clumpy and asymmetrical, with peaks at cometocentric radii ~500-1000km, consistent with release of HNC in collimated outflow(s). Compared to HCN, the H_2_ CO distribution in comet Lemmon is very extended. The interferometric visibility amplitudes are consistent with coma production of H_2_CO and HNC from unidentified precursor material(s) in both comets. Adopting a Haser model, the H_2_CO parent scale length is found to be a few thousand kilometers in Lemmon and only a few hundred kilometers in ISON, consistent with the destruction of the precursor by photolysis or thermal degradation at a rate that scales in proportion to the solar radiation flux.
- ID:
- ivo://CDS.VizieR/J/ApJ/455/60
- Title:
- CFRS II: 0000-00 and 1000+25 fields
- Short Name:
- J/ApJ/455/60
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper describes the methods used to obtain the spectroscopic data and construct redshift catalogs for the Canada-France Deep Redshift Survey (CFRS). The full data set consists of more than 1000 spectra, of objects with 17.5=<I_AB_=<22.5, obtained from deep multislit data with the MARLIN and MOS-SIS spectrographs at the Canada-France-Hawaii Telescope (CFHT). The final spectroscopic catalog contains 200 stars, 591 galaxies with secure redshifts in the range 0=<z=<1.3, six QSOs, and 146 objects with very uncertain or unknown redshifts, leading to an overall success rate of identification of 85%. In addition, 67 objects affected by observational problems have been placed in a supplemental list. We describe here the instrumental setup and the observing procedures used to gather this large data set efficiently. New optimal ways of packing spectra on the detector to increase significantly the multiplexing gain offered by multislit spectroscopy are described. Dedicated data reduction procedures have been developed under the IRAF environment to allow for fast and accurate processing. Very strict procedures have been followed to establish a reliable list of final spectroscopic measurements. Fully independent processing of the data has been carried out by three members of the team for each data set associated with a multislit mask, and final redshifts were assigned only after the careful comparison of the three independent measurements. A confidence class scheme was established. We strongly emphasize the benefits of such procedures. Finally, we present the spectroscopic data obtained for 303 objects in the 0000-00 and 1000+25 fields. The success rate in spectroscopic identification is 83% for the 0000-00 field and 84% for the 1000+25 field.
- ID:
- ivo://CDS.VizieR/J/ApJ/455/75
- Title:
- CFRS III: 1415+52 and 2215+00 fields
- Short Name:
- J/ApJ/455/75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper is one of a series describing the Canada-France Redshift Survey (CFRS). It is shown how the shape of the continuum around the emission line can be used to distinguish between [O II]{lambda}3727 at z>0.76 and H{alpha} at low redshift in spectra for which only a single isolated emission line is visible. Based on this, [O II]{lambda}3727 is most likely to be the emission line in most of the single emission-line galaxies in the CFRS. The statistics of the repeated observations are analyzed to derive an empirical calibration of the reliability of the spectroscopic identifications in the CFRS in order to determine how often additional observations could lead to the identification of an initially unidentified object and to provide an estimate of the internal velocity accuracy. Finally, the results of spectroscopic observations of 413 objects in the 1415+52 and 2215+00 CFRS survey fields are presented.
3308. CFRS IV: 0300+00 field
- ID:
- ivo://CDS.VizieR/J/ApJ/455/88
- Title:
- CFRS IV: 0300+00 field
- Short Name:
- J/ApJ/455/88
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Possible surface brightness selection effects in the redshift catalogs of the Canada-France Redshift Survey are investigated through comparisons of subsamples of the data. Our analyses demonstrate that the securing of redshifts is independent of possible biases arising from surface brightness effects and/or differing galaxy morphologies and orientations. The unusual geometry of the mask designs for our spectroscopic observations also do not produce any significant bias. There is, however, a bias at the highest and lowest redshifts, especially for absorption-line galaxies at z>1 and z<0.2, due to the adopted spectral range (4250-8500A). Apart from the latter, we conclude that our sample of identified galaxies is an unbiased subsample of the original photometric catalog and is essentially limited by I-band flux density (17.5<I_AB_<22.5). Finally, spectroscopic data for the remaining CFRS field is presented. Data for 272 objects in the 0300+0000 field are given.
- ID:
- ivo://CDS.VizieR/J/ApJ/464/79
- Title:
- CFRS XI: High-redshift field galaxies morphology
- Short Name:
- J/ApJ/464/79
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The 143 galaxies with secure redshifts (Z_median_=0.62) from the 1415+52 field of the Canada-France Redshift Survey have been imaged with median seeing of 0.67" (FWHM). Structural parameters have been derived by fitting multicomponent models and the results confirm two phenomena seen in a smaller sample of galaxies imaged with the Hubble Space Telescope. First, 11+/-3% of the galaxies lie off the normal locus of color versus bulge fraction B/T. This class of objects ("blue nucleated galaxies," or BNGs) was identified using HST observations (Schade et al. 1995ApJ...451L...1S, hereafter CFRS IX), and it was shown that they are associated with peculiar/asymmetric structure and merger/interactions. The observed frequency of BNGs in this sample is 14+/-4% 0.5<z<1.2 and 6^+6^_-3_% at 0.2<z<0.5, but the true frequency is likely to be a factor ~2 higher after corrections are made for the effect of asymmetric/peculiar structures. Galaxy disks at 0.5<z<1.1 are found to have a mean rest-frame, inclination-corrected central surface brightness of {mu}_AB_(B)=19.8+/-0.1mag/arcsec^2^, ~1.6mag brighter than the Freeman (1970ApJ...160..811F) value. At low redshift (0.2<z<0.5) the mean surface brightness [{mu}_AB_(B)=21.3+/-0.25] is consistent with the Freeman value. These results are consistent with the HST observations. With larger numbers of galaxies and therefore more statistical weight they demonstrate the capabilities, and limits, of ground-based work in the study of galaxy morphology at high redshift.
- ID:
- ivo://CDS.VizieR/J/ApJ/481/49
- Title:
- CFRS XIV. Field galaxies up to z=1
- Short Name:
- J/ApJ/481/49
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The spectral properties of more than 400 Canada-France Redshift Survey (CFRS) galaxies and their changes over the redshift interval 0<=z<=1.3 are investigated. Emission-line intensities and equivalent widths for accessible lines have been measured, as well as continuum color indices based on 200{AA} wide spectral regions.
