- ID:
- ivo://CDS.VizieR/J/ApJ/841/102
- Title:
- Type 2 AGN host galaxies in Chandra-COSMOS
- Short Name:
- J/ApJ/841/102
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the star formation properties of a large sample of ~2300 X-ray-selected Type 2 Active Galactic Nuclei (AGNs) host galaxies out to z~3 in the Chandra COSMOS Legacy Survey in order to understand the connection between the star formation and nuclear activity. Making use of the existing multi-wavelength photometric data available in the COSMOS field, we perform a multi-component modeling from far-infrared to near-ultraviolet using a nuclear dust torus model, a stellar population model and a starburst model of the spectral energy distributions (SEDs). Through detailed analyses of SEDs, we derive the stellar masses and the star formation rates (SFRs) of Type 2 AGN host galaxies. The stellar mass of our sample is in the range of 9<logM_stellar_/M_{sun}_<12 with uncertainties of ~0.19dex. We find that Type 2 AGN host galaxies have, on average, similar SFRs compared to the normal star-forming galaxies with similar M_stellar_ and redshift ranges, suggesting no significant evidence for enhancement or quenching of star formation. This could be interpreted in a scenario, where the relative massive galaxies have already experienced substantial growth at higher redshift (z>3), and grow slowly through secular fueling processes hosting moderate-luminosity AGNs.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/463/24
- Title:
- Type 2 AGNs with double-peaked narrow emission lines
- Short Name:
- J/MNRAS/463/24
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- 1 per cent of redshift z~0.1 active galactic nuclei (AGNs) show velocity splitting of a few hundred km/s in the narrow emission lines in spatially integrated spectra. Such line profiles have been found to arise from the bulk motion of ionized gas clouds associated with galactic-scale outflows, merging pairs of galaxies each harbouring a supermassive black hole (SMBH), and/or galactic-scale disc rotation. It remains unclear, however, how the frequency of narrow-line velocity splitting may depend on AGN luminosity. Here we study the correlation between the fraction of Type 2 AGNs with double-peaked narrow emission lines and AGN luminosity as indicated by [OIII] {lambda}5007 emission-line luminosity L_[OIII]_. We combine the sample of Liu et al. (2010. Cat. J/ApJ/708/427) at z~0.1 with a new sample of 178 Type 2 AGNs with double-peaked [OIII] emission lines at z~0.5. We select the new sample from a parent sample of 2089 Type 2 AGNs from the SDSS-III/Baryon Oscillation Spectroscopic Survey. We find a statistically significant (~4.2{sigma}) correlation between L_[OIII}]_ and the fraction of objects that exhibit double-peaked narrow emission lines among all Type 2 AGNs, corrected for selection bias and incompleteness due to [OIII] line width, equivalent width, splitting velocity, and/or equivalent width ratio between the two velocity components. Our result suggests that galactic-scale outflows and/or merging pairs of SMBHs are more prevalent in more powerful AGNs, although spatially resolved follow-up observations are needed to resolve the origin(s) for the narrow-line velocity splitting for individual AGNs.
- ID:
- ivo://CDS.VizieR/J/ApJ/708/427
- Title:
- Type 2 AGNs with double-peaked [OIII] lines
- Short Name:
- J/ApJ/708/427
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a sample of 167 type 2 active galactic nuclei (AGNs) with double-peaked [OIII]4959,5007 narrow emission lines, selected from the Seventh Data Release of the Sloan Digital Sky Survey. The double-peaked profiles can be well modeled by two velocity components, blueshifted and redshifted from the systemic velocity. Half of these objects have a more prominent redshifted component. In cases where the H{beta} emission line is strong, it also shows two velocity components whose line-of-sight (LOS) velocity offsets are consistent with those of [OIII]. The relative LOS velocity offset between the two components is typically a few hundred km/s, larger by a factor of ~1.5 than the line full width at half maximum of each component. The offset correlates with the host stellar velocity dispersion {sigma}_*_. The host galaxies of this sample show systematically larger {sigma}_*_, stellar masses, and concentrations, and older luminosity-weighted mean stellar ages than a regular type 2 AGN sample matched in redshift, [OIII]5007 equivalent width, and luminosity; they show no significant difference in radio properties. These double-peaked features could be due to narrow-line region kinematics, or binary black holes.
22574. Type 3 event in Helio
- ID:
- ivo://padc.obspm.helio/hfc1t3/q/epn_core
- Title:
- Type 3 event in Helio
- Short Name:
- HFC1T3
- Date:
- 25 Feb 2025 15:22:41
- Publisher:
- Paris Astronomical Data Centre
- Description:
- type 3 events of the sun from helio database.
- ID:
- ivo://CDS.VizieR/J/MNRAS/448/732
- Title:
- Type Ia SN environment within host galaxies
- Short Name:
- J/MNRAS/448/732
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present constraints on Type Ia supernovae (SNe Ia) progenitors through an analysis of the environments found at the explosion sites of 102 events within star-forming host galaxies. H{alpha} and Galaxy Evolution Explorer near-ultraviolet (UV) images are used to trace on-going and recent star formation (SF), while broad-band B, R, J, K imaging is also analysed. Using pixel statistics we find that SNe Ia show the lowest degree of association with H{alpha} emission of all supernova (SN) types. It is also found that they do not trace near-UV emission. As the latter traces SF on time-scales less than 100Myr, this rules out any extreme 'prompt' delay times as the dominant progenitor channel of SNe Ia. SNe Ia best trace the B-band light distribution of their host galaxies. This implies that the population within star-forming galaxies is dominated by relatively young progenitors. Splitting SNe by their (B-V) colours at maximum light, 'redder' events show a higher degree of association with HII regions and are found more centrally within hosts. We discuss possible explanations of this result in terms of line-of-sight extinction and progenitor effects. No evidence for correlations between SN stretch and environment properties is observed.
- ID:
- ivo://CDS.VizieR/J/ApJ/773/53
- Title:
- Type Ia SNe spectroscopy by the CSP
- Short Name:
- J/ApJ/773/53
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the first release of optical spectroscopic data of low-redshift Type Ia supernovae (SNe Ia) by the Carnegie Supernova Project including 604 previously unpublished spectra of 93 SNe Ia. The observations cover a range of phases from 12 days before to over 150 days after the time of B-band maximum light. With the addition of 228 near-maximum spectra from the literature, we study the diversity among SNe Ia in a quantitative manner. For that purpose, spectroscopic parameters are employed such as expansion velocities from spectral line blueshifts and pseudo-equivalent widths (pW). The values of those parameters at maximum light are obtained for 78 objects, thus providing a characterization of SNe Ia that may help to improve our understanding of the properties of the exploding systems and the thermonuclear flame propagation. Two objects, namely, SNe 2005M and 2006is, stand out from the sample by showing peculiar Si II and S II velocities but otherwise standard velocities for the rest of the ions. We further study the correlations between spectroscopic and photometric parameters such as light-curve decline rate and color. In agreement with previous studies, we find that the pW of Si II absorption features are very good indicators of light-curve decline rate. Furthermore, we demonstrate that parameters such as pW2 (Si II 4130) and pW6 (Si II 5972) provide precise calibrations of the peak B-band luminosity with dispersions of {approx}0.15mag. In the search for a secondary parameter in the calibration of peak luminosity for SNe Ia, we find a {approx}2{sigma}-3{sigma} correlation between B-band Hubble residuals and the velocity at maximum light of S II and Si II lines.
- ID:
- ivo://CDS.VizieR/J/ApJ/796/L18
- Title:
- Type Ia supernova 2011de UVOT photometry
- Short Name:
- J/ApJ/796/L18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present and discuss the ultraviolet (UV)/optical photometric light curves and absolute magnitudes of the Type Ia supernova (SN Ia) 2011de from the Swift Ultraviolet/Optical Telescope. We find it to be the UV brightest SN Ia yet observed - more than a factor of 10 brighter than normal SNe Ia in the mid-ultraviolet. We find that the UV/optical brightness and broad light curve evolution can be modeled with additional flux from the shock of the ejecta hitting a relatively large red giant companion separated by 6x10^13^ cm. However, the post-maximum behavior of other UV-bright SNe Ia can also be modeled in a similar manner, including objects with UV spectroscopy or pre-maximum photometry which is inconsistent with this model. This suggests that similar UV luminosities can be intrinsic or caused by other forms of shock interaction. The high velocities reported for SN 2011de make it distinct from the UV-bright "super-Chandrasekhar" SNe Ia and the NUV-blue group of normal SNe Ia. SN 2011de is an extreme example of the UV variations in SNe Ia.
- ID:
- ivo://CDS.VizieR/J/AJ/131/1648
- Title:
- Type Ia supernovae at high and low redshifts
- Short Name:
- J/AJ/131/1648
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using archival data of low-redshift (z<0.01; Center for Astrophysics and SUSPECT databases) Type Ia supernovae (SNe Ia) and recent observations of high-redshift (0.16<z<0.64) SNe Ia, we study the "uniformity" of the spectroscopic properties of nearby and distant SNe Ia. We find no difference in the measurements we describe here. In this paper we base our analysis solely on line-profile morphology, focusing on measurements of the velocity location of maximum absorption (v_abs_) and peak emission (v_peak_).
- ID:
- ivo://CDS.VizieR/J/ApJ/607/665
- Title:
- Type Ia supernovae at z>1 discovered by HST
- Short Name:
- J/ApJ/607/665
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have discovered 16 Type Ia supernovae (SNe Ia) with the Hubble Space Telescope (HST) and have used them to provide the first conclusive evidence for cosmic deceleration that preceded the current epoch of cosmic acceleration. These objects, discovered during the course of the GOODS ACS Treasury program, include 6 of the 7 highest redshift SNe Ia known, all at z>1.25, and populate the Hubble diagram in unexplored territory. The luminosity distances to these objects and to 170 previously reported SNe Ia have been determined using empirical relations between light-curve shape and luminosity. A purely kinematic interpretation of the SN Ia sample provides evidence at the greater than 99% confidence level for a transition from deceleration to acceleration or, similarly, strong evidence for a cosmic jerk.
- ID:
- ivo://CDS.VizieR/J/MNRAS/389/1871
- Title:
- Type Ia supernovae candidates from SDSS
- Short Name:
- J/MNRAS/389/1871
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In the course of the Sloan Digital Sky Survey (SDSS-I), a large fraction of the surveyed area was observed more than once due to field tiling overlap, usually at different epochs. We utilize some of these data to perform a supernova (SN) survey at a mean redshift of z=0.2. Our archival search, in ~5 per cent of the SDSS-I overlap area, produces 29 SN candidates clearly associated with host galaxies. Using the Bayesian photometric classification algorithm of Poznanski et al. (2002PASP..114..833P), and correcting for classification bias, we find 17 of the 29 candidates are likely Type Ia SNe.
