- ID:
- ivo://CDS.VizieR/J/ApJ/793/101
- Title:
- CANDELS z~2 galaxy properties
- Short Name:
- J/ApJ/793/101
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use CANDELS imaging, 3D-HST spectroscopy, and Chandra X-ray data to investigate if active galactic nuclei (AGNs) are preferentially fueled by violent disk instabilities funneling gas into galaxy centers at 1.3<z<2.4. We select galaxies undergoing gravitational instabilities using the number of clumps and degree of patchiness as proxies. The CANDELS visual classification system is used to identify 44 clumpy disk galaxies, along with mass-matched comparison samples of smooth and intermediate morphology galaxies. We note that despite being mass-matched and having similar star formation rates, the smoother galaxies tend to be smaller disks with more prominent bulges compared to the clumpy galaxies. The lack of smooth extended disks is probably a general feature of the z~2 galaxy population, and means we cannot directly compare with the clumpy and smooth extended disks observed at lower redshift. We find that z~2 clumpy galaxies have slightly enhanced AGN fractions selected by integrated line ratios (in the mass-excitation method), but the spatially resolved line ratios indicate this is likely due to extended phenomena rather than nuclear AGNs. Meanwhile, the X-ray data show that clumpy, smooth, and intermediate galaxies have nearly indistinguishable AGN fractions derived from both individual detections and stacked non-detections. The data demonstrate that AGN fueling modes at z~1.85 - whether violent disk instabilities or secular processes - are as efficient in smooth galaxies as they are in clumpy galaxies.
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- ID:
- ivo://CDS.VizieR/J/ApJS/115/185
- Title:
- 3C 390.3 BVRI and H photometry
- Short Name:
- J/ApJS/115/185
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Results of a ground-based optical monitoring campaign on 3C 390.3 in 1994-1995 are presented. The broadband fluxes (B, V, R, and I), the spectrophotometric optical continuum flux F_{lambda}_(5177{AA}), and the integrated emission-line fluxes of H{alpha}, H{beta}, H{gamma}, He I 5876, and He II {lambda}4686 all show a nearly monotonic increase with episodes of milder short-term variations superposed. The amplitude of the continuum variations increases with decreasing wavelength (4400-9000{AA}). The optical continuum variations follow the variations in the ultraviolet and X-ray with time delays, measured from the centroids of the cross-correlation functions, typically around 5 days, but with uncertainties also typically around 5 days; zero time delay between the high-energy and low-energy continuum variations cannot be ruled out. The strong optical emission lines H{alpha}, H{beta}, H{gamma}, and He I {lambda}5876 respond to the high-energy continuum variations with time delays typically about 20 days, with uncertainties of about 8 days. There is some evidence that He II {lambda}4686 responds somewhat more rapidly, with a time delay of around 10 days, but again, the uncertainties are quite large (~8 days). The mean and rms spectra of the H{alpha} and H{beta} line profiles provide indications for the existence of at least three distinct components located at +/-4000 and 0km/s relative to the line peak. The emission-line profile variations are largest near line center.
- ID:
- ivo://CDS.VizieR/J/A+A/454/333
- Title:
- Computed Hbeta indices from ATLAS9 model
- Short Name:
- J/A+A/454/333
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Grids of H{beta} indices based on updated (new-ODF) ATLAS9 model atmospheres were computed for solar and scaled solar metallicities [+0.5], [+0.2], [0.0], [-0.5], [-1.0], [-1.5], [-2.0], [-2.5] and for alpha enhanced compositions [+0.5a], [0.0a], [-0.5a], [-1.0a], [-1.5a], [-2.0a], [-2.5a], and [-4.0a]. Indices for Teff>5000K were computed with the same methods as described by Lester, Gray & Kurucz (1986ApJS...61..509L) (LGK86) except for a different normalization of the computed natural system to the standard system. LGK86 used special ODFs to compute the fluxes. For Teff less or equal to 5000K we computed the fluxes using the synthetic spectrum method. In order to assess the accuracy of the computed indices comparisons were made with the indices computed by Smalley & Dworetsky (1995A&A...293..446S) (MD95) and with the empirical relations Teff-H{beta} given by Alonso et al. (1996A&A...313..873A) for several metallicities. Furthermore, for cool stars, temperatures inferred from the computed indices were compared with those of the fundamental stars listed by MD95. The same kind of comparison was made between gravities for B-type stars. The temperatures from the computed indices are in good agreement, within the error limits, with the literature values for Teff between 4750K and 8000K, while the gravities agree for Teff>9000K. The computed H{beta} indices for the Sun and for Procyon are very close to the observed values. The comparison between the observed and computed H{beta} indices as function of the observed H{beta} has shown a very small trend which almost completely disappears when only stars hotter than 10000K are considered. The trend due to the cool stars is probably related with the low accuracy of the fundamental Teff which are affected by large errors for most of the stars.
- ID:
- ivo://CDS.VizieR/J/A+A/476/89
- Title:
- HII galaxies narrow-band Hbeta images
- Short Name:
- J/A+A/476/89
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Our aims is to create a catalog of images of HII galaxies and their individual star-formation regions in order to study the distribution of the gas emission and their underlying stellar continuum. We have used H{beta} narrow-band images of 43 selected HII galaxies obtained at ESO NTT 3.58m telescope using the SUSI2 camera. Surface photometric H{beta} fluxes and equivalent widths for all objects and star-formation regions are presented in this catalog.
- ID:
- ivo://CDS.VizieR/J/A+A/391/809
- Title:
- HII regions in NGC 5457 and NGC 4395
- Short Name:
- J/A+A/391/809
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Line intensities, visual extinction, abundances and ionization hardness parameter for HII regions in two spiral galaxies are presented. The following galaxies have been observed: NGC 5457 and NGC 4395. In NGC 5457 have been obtained data for 338 regions. In NGC 4395 have been obtained data for 158 regions. For each region position, visual extinction, H-alpha flux, H-alpha equivalent width, H-beta flux, H-beta equivalent width, [OII] flux, [OIII] flux, [SII] flux, [SIII] flux (only for NGC 5457), R23 parameter, oxygen abundance and ionization hardness parameter (only for NGC 5457) are given.
- ID:
- ivo://CDS.VizieR/J/A+A/658/A188
- Title:
- PHANGS-MUSE sample HII regions catalog
- Short Name:
- J/A+A/658/A188
- Date:
- 02 Mar 2022 06:10:18
- Publisher:
- CDS
- Description:
- We use an unprecedented sample of about 23000 HII regions detected at an average physical resolution of 67pc in the PHANGS-MUSE sample to study the extragalactic HII region H{alpha} luminosity function (LF). Our observations probe the star-forming disk of 19 nearby spiral galaxies with low inclination and located close to the star formation main sequence at z=0. The mean LF slope in our sample is =1.73 with a {sigma} of 0.15. We find that {alpha} decreases with the galaxy's star formation rate surface density {SIGMA}_SFR_ and argue that this is driven by an enhanced clustering of young stars at high gas surface densities. Looking at the HII regions within single galaxies we find that no significant variations occur between the LF of the inner and outer part of the star-forming disk, whereas the LF in the spiral arm areas is shallower than in the inter-arm areas for six out of the 13 galaxies with clearly visible spiral arms. We attribute these variations to the spiral arms increasing the molecular clouds arm-inter-arm mass contrast and find suggestive evidence that they are more evident for galaxies with stronger spiral arms. Furthermore, we find systematic variations in {alpha} between samples of HII regions with high and low ionization parameter q and argue that they are driven by the aging of HII regions.
- ID:
- ivo://CDS.VizieR/J/A+A/639/A23
- Title:
- Photometry & spectroscopy of EE Cep: 2014-15
- Short Name:
- J/A+A/639/A23
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- EE Cep is one of few eclipsing binary systems with a dark, dusty disk around an invisible object similar to epsilon Aur. The system is characterized by grey and asymmetric eclipses every 5.6yr, with a significant variation in their photometric depth, ranging from ~0.5mag to ~2.0mag. The main aim of the observational campaign of the EE Cep eclipse in 2014 was to test the model of disk precession (Galan et al. 2012). We expected that this eclipse would be one of the deepest with a depth of ~2m.mag. We collected multicolor observations from almost 30 instruments located in Europe and North America. This photometric data covers 243 nights during and around the eclipse. We also analyse the low- and high- resolution spectra from several instruments. The eclipse was shallow with a depth of 0m.71 in V-band. The multicolor photometry illustrates small color changes during the eclipse with a total amplitude of order ~+0.15mag in B-I color index. The linear ephemeris for this system is updated by including new times of minima, measured from the three most recent eclipses at epochs E=9, 10 and 11. New spectroscopic observations were acquired, covering orbital phases around the eclipse, which were not observed in the past and increased the data sample, filling some gaps and giving a better insight into the evolution of the H{alpha} and NaI spectral line profiles during the primary eclipse. The eclipse of EE Cep in 2014 was shallower than expected 0.71mag instead of ~2.0mag. This means that our model of disk precession needs revision.
- ID:
- ivo://CDS.VizieR/J/ApJ/876/102
- Title:
- Reverberation mapping of the Seyfert Zw I 1
- Short Name:
- J/ApJ/876/102
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report results of the first reverberation mapping campaign of I Zwicky 1 during 2014-2016, which showed unambiguous reverberations of the broad H{beta} line emission in the varying optical continuum. From analysis using several methods, we obtain a reverberation lag of {tau}_H{beta}_=37.2_-4.9_^+4.5^days. Taking a virial factor of f_BLR_=1, we find a black hole mass of M_{bullet}_=9.30_-1.38_^+1.26^x10^6^M_{sun}_ from the mean spectra. The accretion rate is estimated to be 203.9_-65.8_^+61.0^L_Edd_c^-2^, suggesting a super-Eddington accretor, where LEdd is the Eddington luminosity and c is the speed of light. By decomposing Hubble Space Telescope images, we find that the stellar mass of the bulge of its host galaxy is log(M_bulge_/M_{sun}_)=10.92+/-0.07. This leads to a black hole to bulge mass ratio of ~10^-4^, which is significantly smaller than that of classical bulges and elliptical galaxies. After subtracting the host contamination from the observed luminosity, we find that I Zw 1 follows the empirical R_BLR_{propto}L_5100_^1/2^ relation.
- ID:
- ivo://CDS.VizieR/J/other/SAAOC/15.53
- Title:
- Southern reddened luminous stars. II.
- Short Name:
- J/other/SAAOC/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- H{beta} photometry is given for 263 reddened and very reddened stars from the Stephenson & Sanduleak (1971, Cat. <III/43>) catalogue of Luminous Stars in the Southern Milky Way (LSS). The results are combined with the uvby photometry presented in Paper I to determine reddenings, E(b-y), and distances for the stars and to estimate the spectral types and luminosity classes from derived T_eff_ and M_V_ values.
- ID:
- ivo://CDS.VizieR/J/ApJS/82/117
- Title:
- UBV and H-beta in Sco-Cen association
- Short Name:
- J/ApJS/82/117
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As part of a thorough study of the luminosity function of Sco-Cen, UBV, and H_{beta}_ photometry has been acquired for a large number of mid B- to late A-type stars which are within or surrounding the Scorpius-Centaurus OB association. UBV and H_{beta}_ photoelectric measures have been obtained for all the B stars without previous observations and for many of those with in the large field 280deg<=l<=362deg, +10deg<=b<=+40deg, and m-M<=7.5mag. Within the upper Scopius subgroup (ScoOB2), 341deg<=l<=362deg, +10=<b=<30deg, UBV and H_{beta}_ photometry was obtained for all B stars listed in the MSC(HD) catalog. As well, UBV measures were obtained for all the A-type stars within this field.
