- ID:
- ivo://CDS.VizieR/J/A+A/383/823
- Title:
- Radial velocities of UCOs in Fornax
- Short Name:
- J/A+A/383/823
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The relation between the Ultra Compact Objects (hereafter UCOs) recently discovered in the Fornax cluster (Drinkwater et al., 2000PASA...17..227D; Hilker et al., 1999, Cat. <J/A+AS/134/75>) and the brightest globular clusters associated with the central galaxy NGC 1399 has been investigated. A spectroscopic survey on compact objects in the central region of the Fornax cluster was carried out with the 2.5 m du Pont telescope (LCO) at Las Campanas, in the three nights of 2000/12/30 to 2001/01/01. The magnitude limit was approx. V=21 mag, the spectral resolution approx. 4{AA}. UCOs and the bright NGC 1399 globular clusters with similar brightness were inspected. 12 GCs from the bright end of the globular cluster luminosity function have been identified as Fornax members. Eight are new members, four were known as members from before.
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2922. Radial velocity in Draco
- ID:
- ivo://CDS.VizieR/J/MNRAS/330/792
- Title:
- Radial velocity in Draco
- Short Name:
- J/MNRAS/330/792
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present stellar radial velocity data for the Draco dwarf spheroidal (dSph) galaxy obtained using the AF2/WYFFOS instrument combination on the William Herschel Telescope. Our data set consists of 186 member stars, 159 of which have good quality velocities, extending to a magnitude V~19.5 with a mean velocity precision of ~2km/s. As this survey is based on a high-precision photometric target list, it contains many more Draco members at large radii. For the first time, this allows a robust determination of the radial behaviour of the velocity dispersion in a dSph.
- ID:
- ivo://CDS.VizieR/J/MNRAS/436/1302
- Title:
- Radiation fields in star-forming galaxies
- Short Name:
- J/MNRAS/436/1302
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We provide a library of diffuse stellar radiation fields in spiral galaxies derived using calculations of the transfer of stellar radiation from the main morphological components - discs, thin discs and bulges - through the dusty interstellar medium. These radiation fields are self-consistent with the solutions for the integrated panchromatic spectral energy distributions (SEDs) previously presented using the same model. Because of this, observables calculated from the radiation fields, such as gamma-ray or radio emission, can be self-consistently combined with the solutions for the ultraviolet/optical/submillimeter SEDs, thus expanding the range of applicability of the radiation transfer model to a broader range of wavelengths and physical quantities.
- ID:
- ivo://CDS.VizieR/J/MNRAS/470/2539
- Title:
- Radiation fields of the Milky Way
- Short Name:
- J/MNRAS/470/2539
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We provide a library for the ultraviolet - submillimetre (submm) interstellar radiation fields (ISRFs) of the Milky Way (MW), derived from modelling COBE, IRAS and Planck maps of the all-sky emission in the near-, mid-, far-infrared and submm. The library was produced using the axisymmetric radiative transfer model that we have previously implemented to model the panchromatic spectral energy distributions (SEDs) of star-forming galaxies in the nearby universe, but with a new methodology allowing for optimization of the radial and vertical geometry of stellar emissivity and dust opacity, as deduced from the highly resolved emission seen from the vantage point of the Sun.
- ID:
- ivo://CDS.VizieR/J/A+A/629/A134
- Title:
- Radiative contribution from stripped stars
- Short Name:
- J/A+A/629/A134
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Stars stripped of their envelopes from interaction with a binary companion emit a significant fraction of their radiation as ionizing photons. They are potentially important stellar sources of ionizing radiation, however, they are still often neglected in spectral synthesis simulations or simulations of stellar feedback. In anticipating the large datasets of galaxy spectra from the upcoming James Webb Space Telescope, we modeled the radiative contribution from stripped stars by using detailed evolutionary and spectral models. We estimated their impact on the integrated spectra and specifically on the emission rates of HI-, HeI-, and HeII-ionizing photons from stellar populations. We find that stripped stars have the largest impact on the ionizing spectrum of a population in which star formation halted several Myr ago. In such stellar populations, stripped stars dominate the emission of ionizing photons, mimicking a younger stellar population in which massive stars are still present. Our models also suggest that stripped stars have harder ionizing spectra than massive stars. The additional ionizing radiation, with which stripped stars contribute affects observable properties that are related to the emission of ionizing photons from stellar populations. In co-eval stellar populations, the ionizing radiation from stripped stars increases the ionization parameter and the production efficiency of hydrogen ionizing photons. They also cause high values for these parameters for about ten times longer than what is predicted for massive stars. The effect on properties related to non-ionizing wavelengths is less pronounced, such as on the ultraviolet continuum slope or stellar contribution to emission lines. However, the hard ionizing radiation from stripped stars likely introduces a characteristic ionization structure of the nebula, which leads to the emission of highly ionized elements such as O^2+^ and C^3+^. We, therefore, expect that the presence of stripped stars affects the location in the BPT diagram and the diagnostic ratio of OIII to OII nebular emission lines. Our models are publicly available through CDS database and on the STARBURST99 website.
- ID:
- ivo://CDS.VizieR/J/MNRAS/445/955
- Title:
- Radio-AGN feedback for 0.5<z<1
- Short Name:
- J/MNRAS/445/955
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents the first measurement of the radio luminosity function of 'jet-mode' (radiatively inefficient) radio-AGN out to z=1, in order to investigate the cosmic evolution of radio-AGN feedback. Eight radio source samples are combined to produce a catalogue of 211 radio-loud AGN with 0.5<z<1.0, which are spectroscopically classified into jet-mode and radiative-mode (radiatively efficient) AGN classes. Comparing with large samples of local radio-AGN from the Sloan Digital Sky Survey, the cosmic evolution of the radio luminosity function of each radio-AGN class is independently derived. Radiative-mode radio-AGN show an order of magnitude increase in space density out to z~1 at all luminosities, consistent with these AGN being fuelled by cold gas. In contrast, the space density of jet-mode radio-AGN decreases with increasing redshift at low radio luminosities (L_1.4GHz_<~10^24^W/Hz) but increases at higher radio luminosities. Simple models are developed to explain the observed evolution. In the best-fitting models, the characteristic space density of jet-mode AGN declines with redshift in accordance with the declining space density of massive quiescent galaxies, which fuel them via cooling of gas in their hot haloes. A time delay of 1.5-2Gyr may be present between the quenching of star formation and the onset of jet-mode radio-AGN activity. The behaviour at higher radio luminosities can be explained either by an increasing characteristic luminosity of jet-mode radio-AGN activity with redshift (roughly as (1+z)^3^) or if the jet-mode radio-AGN population also includes some contribution of cold-gas-fuelled sources seen at a time when their accretion rate was low. Higher redshifts measurements would distinguish between these possibilities.
- ID:
- ivo://CDS.VizieR/J/MNRAS/413/2314
- Title:
- Radio and mid-IR counterpart of submm galaxies
- Short Name:
- J/MNRAS/413/2314
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present radio and infrared (3.6-24um) counterparts to submillimetre galaxies (SMGs) detected in the Extended Chandra Deep Field-South with the Large APEX Bolometer Camera (LABOCA) 870um bolometer camera on the 12m Atacama Pathfinder Experiment. Using the Very Large Array at .4GHz and Spitzer, we have identified secure counterparts to 79 of the 126 SMGs [signal-to-noise ratio (S/N)>3.7, S870>4.4mJy] in the field, 62 via their radio and/or 24um emission, the remainder using a colour-flux cut on Infrared Array Camera 3.6um and 5.8um sources chosen to maximize the number of secure, coincident radio and 24um counterparts.
- ID:
- ivo://CDS.VizieR/J/ApJ/688/826
- Title:
- Radio and X-ray-emitting broad-line AGNs
- Short Name:
- J/ApJ/688/826
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use a recently released SDSS catalog of X-ray-emitting AGNs in conjunction with the FIRST radio survey to investigate the black hole (BH) fundamental plane relationship between the 1.4GHz radio luminosity (L_r_), 0.1-2.4keV X-ray luminosity (L_X_), and black hole mass (M), namely, logL_r_={xi}_RX_logL_X_+{xi}_RM_logM+constant. For this purpose, we compile a large sample of 725 broad-line AGNs, which consists of 498 radio-loud sources and 227 radio-quiet sources. We confirm that radio-loud objects have a steeper slope ({xi}_RX_) with respect to radio-quiet objects and that the dependence of the BH fundamental plane on the BH mass ({xi}_RM_) is weak.
- ID:
- ivo://CDS.VizieR/J/A+A/592/A94
- Title:
- Radio continuum and gas reservoir in NGC 3998
- Short Name:
- J/A+A/592/A94
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the nearby lenticular galaxy NGC 3998. This galaxy is known to host a low-power radio AGN with a kpc-size one-sided jet and a large, nearly polar HI disc. It is therefore a good system to study to understand the relation between the availability of cold-gas and the triggering of AGNs in galaxies. Our new WSRT data reveal two faint, S-shaped radio lobes extending out to ~10 kpc from the galaxy centre. Remarkably, we find that the inner HI disc warps back towards the stellar mid-plane in a way that mirrors the warping of the radio lobes. We suggest that the polar HI disc was accreted through a minor merger, and that the torques causing it to warp in the inner regions are also responsible for feeding the AGN. The "S" shape of the radio lobes would then be due to the radio jets adapting to the changing angular momentum of the accreted gas. The extended radio jets are likely poorly collimated, which would explain their quick fading and, therefore, their rarity in galaxies similar to NGC 3998. The fuelling of the central super-massive black hole is likely occurring via "discrete events", suggested by the observed variability of the radio core and the extremely high core dominance, which we attribute to the formation and ejection of a new jet resulting from a recent fuelling event.
- ID:
- ivo://CDS.VizieR/J/A+A/418/1
- Title:
- Radio continuum spectra in Virgo cluster region
- Short Name:
- J/A+A/418/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New radio continuum observations of galaxies in the Virgo cluster region at 4.85, 8.6, and 10.55GHz are presented. These observations are combined with existing measurements at 1.4 and 0.6GHz. The sample includes 81 galaxies where spectra with more than two frequencies could be derived. Galaxies that show a radio-FIR excess exhibit central activity (HII, LINER,AGN). The four Virgo galaxies with the highest absolute radio excess are found within 2 degrees of the center of the cluster. Galaxies showing flat radio spectra also host active centers. There is no clear trend between the spectral index and the galaxy's distance to the cluster center.
