- ID:
- ivo://CDS.VizieR/J/MNRAS/469/492
- Title:
- JCMT/SCUBA2 objects in COSMOS and UDS fields
- Short Name:
- J/MNRAS/469/492
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present physical properties [redshifts (z), star-formation rates (SFRs) and stellar masses (M*)] of bright (S_850_>=4mJy) submm galaxies in the ~=2deg^2^ COSMOS and UDS fields selected with SCUBA-2/JCMT. We complete the galaxy identification process for all (~=2000) S/N>=3.5 850-{mu}m sources, but focus our scientific analysis on a high-quality subsample of 651 S/N>=4 sources with complete multiwavelength coverage including 1.1-mm imaging. We check the reliability of our identifications, and the robustness of the SCUBA-2 fluxes by revisiting the recent ALMA follow-up of 29 sources in our sample. Considering >4mJy ALMA sources, our identification method has a completeness of ~=86 per cent with a reliability of ~=92 per cent, and only ~=15-20 per cent of sources are significantly affected by multiplicity (when a secondary component contributes >1/3 of the primary source flux). The impact of source blending on the 850-{mu}m source counts as determined with SCUBA-2 is modest; scaling the single-dish fluxes by ~=0.9 reproduces the ALMA source counts. For our final SCUBA-2 sample, we find median z=2.40^+0.10^_-0.04_, SFR=287+/-6M_{sun}_/yr and log(M*/M_{sun)_=11.12+/-0.02 (the latter for 349/651 sources with optical identifications). These properties clearly locate bright submm galaxies on the high-mass end of the 'main sequence' of star-forming galaxies out to z~= 6, suggesting that major mergers are not a dominant driver of the high-redshift submm-selected population. Their number densities are also consistent with the evolving galaxy stellar mass function. Hence, the submm galaxy population is as expected, albeit reproducing the evolution of the main sequence of star-forming galaxies remains a challenge for theoretical models/simulations.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/611/A22
- Title:
- Jekyll & Hyde galaxies ALMA cube & spectrum
- Short Name:
- J/A+A/611/A22
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We obtained ALMA spectroscopy and deep imaging to investigate the origin of the unexpected sub-millimeter emission toward the most distant quiescent galaxy known to date, ZF-COSMOS-20115 at z=3.717. We show here that this sub-millimeter emission is produced by another massive (M*~10^11^M_{sun}_), compact (r_1/2_=0.67+/-0.14kpc) and extremely obscured galaxy (A_V_~3.5), located only 0.4300 (3.1kpc) away from the quiescent galaxy. We dub the quiescent and dusty galaxies Jekyll and Hyde, respectively. No dust emission is detected at the location of the quiescent galaxy, implying SFR<13M_{sun}_/yr which is the most stringent upper limit ever obtained for a quiescent galaxy at these redshifts. The two sources are spectroscopically confirmed to lie at the same redshift thanks to the detection of [CII]158 in Hyde (z=3.709), which provides one the few robust redshifts for a highly-obscured "H-dropout" galax (H-[4.5]=5.1+/-0.8). The [CII] line shows a clear rotating-disk velocity profile which is blueshifted compared to the Balmer lines of Jekyll by 549+/-60km/s, demonstrating that it is produced by another galaxy. Careful de-blending of the Spitzer imaging confirms the existence of this new massive galaxy, and its non-detection in the Hubble images requires extremely red colors and strong attenuation by dust. Full modeling of the UV-to-far-IR emission of both galaxies shows that Jekyll has fully quenched at least 200Myr prior to observation and still presents a challenge for models, while Hyde only harbors moderate star-formation with SFR<~120M_{sun}/yr, and is located at least a factor 1.4 below the z~4 main sequence. Hyde could also have stopped forming stars less than 200Myr before being observed; this interpretation is also suggested by its compactness comparable to that of z~4 quiescent galaxies and its low [CII]/FIR ratio, but significant on-going star-formation cannot be ruled out. Lastly, we find that despite its moderate SFR, Hyde hosts a dense reservoir of gas comparable to that of the most extreme starbursts. This suggests that whatever mechanism has stopped or reduced its star-formation must have done so without expelling the gas outside of the galaxy. Because of their surprisingly similar mass, compactness, environment and star-formation history, we argue that Jekyll and Hyde can be seen as two stages of the same quenching process, and provide a unique laboratory to study this poorly understood phenomenon.
- ID:
- ivo://CDS.VizieR/J/AJ/151/78
- Title:
- Jellyfish galaxy candidates in galaxy clusters
- Short Name:
- J/AJ/151/78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Galaxies that are being stripped of their gas can sometimes be recognized from their optical appearance. Extreme examples of stripped galaxies are the so-called "jellyfish galaxies" that exhibit tentacles of debris material with a characteristic jellyfish morphology. We have conducted the first systematic search for galaxies that are being stripped of their gas at low-z (z=0.04-0.07) in different environments, selecting galaxies with varying degrees of morphological evidence for stripping. We have visually inspected B- and V-band images and identified 344 candidates in 71 galaxy clusters of the OMEGAWINGS+WINGS sample and 75 candidates in groups and lower mass structures in the PM2GC sample. We present the atlas of stripping candidates and a first analysis of their environment and their basic properties, such as morphologies, star formation rates and galaxy stellar masses. Candidates are found in all clusters and at all clustercentric radii, and their number does not correlate with the cluster velocity dispersion {sigma} or X-ray luminosity L_X_. Interestingly, convincing cases of candidates are also found in groups and lower mass halos (10^11^-10^14^M_{sun}_), although the physical mechanism at work needs to be securely identified. All the candidates are disky, have stellar masses ranging from log M/M_{sun}_<9 to >11.5 and the majority of them form stars at a rate that is on average a factor of 2 higher (2.5{sigma}) compared to non-stripped galaxies of similar mass. The few post-starburst and passive candidates have weak stripping evidence. We conclude that disturbed morphologies suggestive of stripping phenomena are ubiquitous in clusters and could be present even in groups and low mass halos. Further studies will reveal the physics of the gas stripping and clarify the mechanisms at work.
- ID:
- ivo://CDS.VizieR/J/A+A/658/A119
- Title:
- Jet collimation in NGC 1052
- Short Name:
- J/A+A/658/A119
- Date:
- 22 Feb 2022 14:52:38
- Publisher:
- CDS
- Description:
- With the increased sensitivity and resolution of radio interferometry the study of the collimation and acceleration region of jets in Active Galactic Nuclei(AGN) has come into focus within the last years. Whereas a large fraction of AGN jets reveal a change from parabolic to conical collimation around the Bondi radius, a small number of sources deviate from this standard picture, including the radio galaxy NGC1052. We study the jet width profile, which provides valuable information about the interplay between the central engine and accretion disk system and the collimation and acceleration zone of the jets. We observed the double-sided active galaxy NGC1052 at six frequencies with the VLBA in 2017 and at 22GHz with RadioAstron in 2016. These data are combined with archival 15, 22, and 43GHz multi-epoch VLBA observations. From ridge-line fitting we obtained width measurements along the jet and counter-jet which were fitted with broken power-laws. We find a break in the jet collimation profile at ~10^4^R_s_ (Schwarzschild radii). Downstream of the break the collimation is conical with a power-law index of 1.0-1.2 (cylindrical 0; parabolic 0.5; conical 1). The upstream power-law index of 0.36 for the approaching jet is neither cylindrical nor parabolic and for the receding jet with 0.16 close-to cylindrical. Both jets have an opening angle of ~30 degree at a distance of ~10^3R_S_ and are well collimated with an opening angle of <10 degrees downstream of the break. There are significant differences in the upstream collimation profile between approaching (Eastern) and receding (Western) jet. Absorption or scattering in the surrounding torus as well as an accretion wind may mimic a cylindrical profile. We need to increase the observing frequencies, which do not suffer from absorption to find the true jet collimation profile upstream of 10^4^R_s_.
- ID:
- ivo://CDS.VizieR/J/A+A/647/A67
- Title:
- Jet collimation in NGC 315
- Short Name:
- J/A+A/647/A67
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The collimation of relativistic jets in galaxies is a poorly understood process. Detailed radio studies of the jet collimation region have been performed so far in a few individual objects, providing important constraints for jet formation models. However, the extent of the collimation zone as well as the nature of the external medium possibly confining the jet are still debated. In this article, we present a multifrequency and multiscale analysis of the radio galaxy NGC 315, including the use of mm-VLBI data up to 86GHz, aimed at revealing the evolution of the jet collimation profile. We then consider results from the literature to compare the jet expansion profile in a sample of 27 low-redshift sources, mainly comprising radio galaxies and BL Lacs, which were classified based on the accretion properties as low-excitation (LEG) and high-excitation (HEG) galaxies. We propose that the jet collimation in NGC 315 is completed on sub-parsec scales. A transition from a parabolic to conical jet shape is detected at z_t_=0.58+/-0.28-parsecs or ~5x10^3& Schwarzschild radii (Rs) from the central engine, a distance which is much smaller than the Bondi radius, rB~92pc, estimated based on X-ray data. The jet in this and in a few other LEG in our sample may be initially confined by a thick disk extending out to ~10^3^-10^4^R_{sun}_. A comparison between the mass-scaled jet expansion profiles of all sources indicates that jets in HEG are surrounded by thicker disk-launched sheaths and collimate on larger scales with respect to jets in LEG. These results suggest that disk winds play an important role in the jet collimation mechanism, particularly in high-luminosity sources. The impact of winds on the origin of the FRI and FRII dichotomy in radio galaxies is also discussed.
1876. Jet-disk symbiosis II
- ID:
- ivo://CDS.VizieR/J/A+A/298/375
- Title:
- Jet-disk symbiosis II
- Short Name:
- J/A+A/298/375
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the correlation between the accretion disk (UV) luminosity and the radio core emission of a quasar sample, containing all PG quasars, also deriving empirical conversion factors from emission line luminosities to disk luminosities. This method allows us to investigate the radio properties of AGN on the absolute scale set by the accretion power. The tables contain the quasar (and radio galaxy) sample discussed in this paper (including the complete PG quasars sample) and give the derived `disk luminosities' of the UV-bump and 5GHz radio luminosities.
- ID:
- ivo://CDS.VizieR/J/A+A/633/A127
- Title:
- Jet-driven outflow in ESO 420-G13
- Short Name:
- J/A+A/633/A127
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A prominent jet-driven outflow of CO(2-1) molecular gas is found along the kinematic minor axis of the Seyfert 2 galaxy ESO 420-G13, at a distance of 340-600pc from the nucleus. The wind morphology resembles a characteristic funnel shape, formed by a highly collimated filamentary emission at the base, likely tracing the jet propagation through a tenuous medium, until a bifurcation point at 440pc where the jet hits a dense molecular core and shatters, dispersing the molecular gas into several clumps and filaments within the expansion cone. We also trace the jet in ionised gas within the inner ~340pc using the [NeII]12.8um line emission, where the molecular gas follows a circular rotation pattern. The wind outflow carries a mass of ~8x10^6^M_{sun}_ at an average wind projected speed of ~160km/s, which implies a mass outflow rate of ~14M_{sun}_/yr. Based on the structure of the outflow and the budget of energy and momentum, we discard radiation pressure from the active nucleus, star formation, and supernovae as possible launching mechanisms. ESO 420-G13 is the second case after NGC 1377 where the presence of a previously unknown jet is revealed due to its interaction with the interstellar medium, suggesting that unknown jets in feeble radio nuclei might be more common than expected. Two possible jet-cloud configurations are discussed to explain the presence of an outflow at such distance from the AGN. The outflowing gas will likely not escape, thus a delay in the star formation rather than quenching is expected from this interaction, while the feedback effect would be confined within the central few hundred parsecs of the galaxy.
- ID:
- ivo://CDS.VizieR/J/ApJ/453/616
- Title:
- JHKL photometry of 12 micron galaxy sample
- Short Name:
- J/ApJ/453/616
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Aperture photometry from our own observations and the literature is presented for the 12 um galaxies in the near-infrared J, H, and K bands and, in some cases, in the L band. These data are corrected to "total" near-infrared magnitudes (with a typical uncertainty of 0.3mag) for a direct comparison with our IRAS fluxes which apply to the entire galaxy. The corrected data are used to derive integrated total near-infrared and far-infrared luminosities. We then combine these with blue photometry and an estimate of the flux contribution from cold dust at wavelengths longward of 100um to derive the first bolometric luminosities for a large sample of galaxies. The presence of nonstellar radiation at 2-3um correlates very well with nonstellar IRAS colors. This enables us to identify a universal Seyfert nuclear continuum from near- to far-infrared wavelengths. Thus, there is a sequence of infrared colors which runs from a pure "normal galaxy" to a pure Seyfert/quasar nucleus. Seyfert 2 galaxies fall close to this same sequence, although only a few extreme narrow-line Seyfert galaxies have quasar-like colors, and these show strong evidence of harboring an obscured broad-line region. A corollary is that the host galaxies of Seyfert nuclei have normal near- to far-infrared spectra on average. Starburst galaxies lie significantly off the sequence, having a relative excess of 60um emission probably as a result of stochastically heated dust grains. We use these correlations to identify several combinations of infrared colors which discriminate between Seyfert 1 and 2 galaxies, LINERs, and ultraluminous starbursts. In the infrared, Seyfert 2 galaxies are much more like Seyfert 1s than they are like starbursts, presumably because both kinds of Seyferts are heated by a single central source, rather than a distributed region of star formation. Moreover, combining the [25-2.2um] color with the [60-12um] color, it appears that Seyfert 1 galaxies are segregated from Seyfert 2 galaxies and starburst galaxies in a well-defined region characterized by the hottest colors, corresponding to the flattest spectral slopes. Virtually no Seyfert 2 galaxy is present in such a region. To reconcile this with the "unified scheme" for Seyfert 1 and 2 galaxies would therefore require that the higher frequency radiation from the nuclei of Seyfert 2 galaxies to be absorbed by intervening dust and re-emitted at lower frequencies. We find that bolometric luminosity is most closely proportional to 12um luminosity. The 60 and 25um luminosities rise faster than linearly with bolometric luminosity, while the optical flux rises less than linearly with bolometric luminosity. This result is a confirmation of the observation that more luminous disk galaxies have relatively more dust-enshrouded stars. Increases in the dust content shifts luminosity from the optical to 25-60um, while leaving a "pivot point" in the mid-IR essentially unchanged. Thus, 12um selection is the closest available approximation to selection by a limiting bolometric flux, which is approximately 14 times nu.L_nu at 12um for non-Seyfert galaxies. It follows that future deep surveys in the mid-infrared, at wavelengths of 8-12um, will simultaneously provide complete samples to different bolometric flux levels of normal and active galaxies, which will not suffer the strong selection effects present both in the optical-UV and far-infrared.
- ID:
- ivo://CDS.VizieR/J/AJ/135/1993
- Title:
- JHK magnitudes of Sculptor dSph RR Lyrae
- Short Name:
- J/AJ/135/1993
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained single-phase near-infrared magnitudes in the J and K bands for a sample of 78 RR Lyrae stars in the Sculptor dSph galaxy.
- ID:
- ivo://CDS.VizieR/J/MNRAS/365/439
- Title:
- JHK photometry for UKIRT faint galaxies
- Short Name:
- J/MNRAS/365/439
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a multicolour catalogue of faint galaxies situated close to bright stars, V<15, with the aim of identifying high-redshift galaxies suitable for study with adaptive optics-equipped near-infrared imagers and spectrographs. The catalogue is constructed from archival calibration observations of the United Kingdom Infrared Telescope (UKIRT) Faint Standard stars with the UKIRT Fast Track Imager (UFTI) camera on UKIRT. We have analysed the deepest 16 fields from the archive to provide a catalogue of galaxies brighter than K~20.3 lying between 3 and 25-arcsec of the guide stars. We identify 111 objects in a total survey area of 8.7arcmin^2^. Of these, 87 are classified as galaxies based on their light profiles in our ~0.5arcsec median seeing K-band images. 12 of the galaxies have (J-K)>~2.0 consistent with them lying at high redshifts, z>~2. These 12 very red galaxies have K-band magnitudes of K=18.1-20.1 and separations from the guide stars of 4-20arcsec and hence are very well suited to adaptive optics studies to investigate their morphologies and spectral properties on sub-kpc scales. We provide coordinates and JHK photometry for all catalogued objects.