- ID:
- ivo://CDS.VizieR/J/AJ/132/1256
- Title:
- eim BATC photometry of OJ 287
- Short Name:
- J/AJ/132/1256
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of our optical monitoring of the BL Lacertae object OJ 287 during the first half of 2005. The source did not show large-amplitude variations during this period and was in a relatively quiescent state. A possible period of 40 days was derived from its light curves in three BATC wave bands. A bluer-when-brighter chromatism was discovered, which is different from the extremely stable color during the outburst in 1994-1996. The different color behaviors imply different variation mechanisms in the two states. We then revisited the optical data on OJ 287 from the OJ-94 project and also found a probable period of 40 days in its optical variability during the late 1994 outburst. The results suggest that two components contribute to the variability of OJ 287 during its outburst state. The first component is the normal blazar variation. This component has an amplitude similar to that of the quiescent state and also may share a similar periodicity. The second component can be taken as a "low-frequency modulation" to the first component. It may be induced by the interaction of the assumed binary black holes in the center of this object. The 40 day period may be related to the helical structure of the magnetic field at the base of the jet or to the orbital motion close to the central primary black hole.
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- ID:
- ivo://CDS.VizieR/J/A+A/623/A123
- Title:
- Einasto parameters for SPARC galaxies
- Short Name:
- J/A+A/623/A123
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Dark matter-baryon scaling relations in galaxies are important in order to constrain galaxy formation models. Here, we provide a modern quantitative assessment of those relations, by modelling the rotation curves of galaxies from the Spitzer Photometry and Accurate Rotation Curves (SPARC) database with the Einasto dark halo model. We focus in particular on the comparison between the original SPARC parameters, with constant mass-to-light ratios for bulges and disks, and the parameters for which galaxies follow the tightest radial acceleration relation. We show that fits are improved in the second case, and that the pure halo scaling relations also become tighter. We report that the density at the radius where the slope is -2 is strongly anticorrelated to this radius, and to the Einasto index. The latter is close to unity for a large number of galaxies, indicative of large cores. In terms of dark matter-baryon scalings, we focus on relations between the core properties and the extent of the baryonic component, which are relevant to the cusp-core transformation process. We report a positive correlation between the core size of halos with small Einasto index and the stellar disk scale-length, as well as between the averaged dark matter density within 2kpc and the baryon-induced rotational velocity at that radius. This finding is related to the consequence of the radial acceleration relation on the diversity of rotation curve shapes, quantified by the rotational velocity at 2kpc. While a tight radial acceleration relation slightly decreases the observed diversity compared to the original SPARC parameters, the diversity of baryon-induced accelerations at 2kpc is sufficient to induce a large diversity, incompatible with current hydrodynamical simulations of galaxy formation, while maintaining a tight radial acceleration relation.
- ID:
- ivo://CDS.VizieR/J/ApJ/698/2114
- Title:
- Einstein A coeff. for ^12^C_2_D_2_ transitions
- Short Name:
- J/ApJ/698/2114
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Two hundred and fifty-one ^12^C_2_D_2_ transitions have been measured in the 0.2-1.6THz region of its nu_5_-nu_4_ difference band and 202 of them were observed for the first time. The accuracy of these measurements is estimated to be ranging from 50kHz to 100kHz. The ^12^C_2_D_2_ molecules were generated under room temperature by passing 120-150mTorr D_2_O vapor through calcium carbide (CaC_2_) powder. A multistate analysis was carried out for the bending vibrational modes nu_4_ and nu_5_ of ^12^C_2_D_2_, which includes the lines observed in this work and prior microwave, far-infrared and infrared data on the pure bending levels. Significantly improved molecular parameters were obtained for ^12^C_2_D_2_ by adding the new measurements to the old data set, which had only 10 lines with microwave measurement precision. New frequency and intensity predictions have been made based on the obtained molecular parameters. The more precise measurements and new predictions reported here will support the analyses of astronomical observations by the future high-resolution spectroscopy telescopes such as Herschel, SOFIA, and ALMA, which will work in the terahertz spectral region.
- ID:
- ivo://CDS.VizieR/J/A+A/376/333
- Title:
- Einstein A-coefficients for C_3_H_4_
- Short Name:
- J/A+A/376/333
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Following tentative detection of cyclopropene (C_3_H_4_) in Sgr B2 through its transition 3_22_-2_21_, several attempts to confirm the presence of cyclopropene in astronomical objects (including Sgr B2 itself) have been made. We suggest that cyclopropene may be observed in astronomical objects through its transition 2_20_-2_21_ at 3.67218GHz, in absorption, even against the cosmic 2.7K background, in a region having low density and low kinetic temperature.
- ID:
- ivo://CDS.VizieR/J/A+A/402/1
- Title:
- Einstein A-coefficients for C3H2 and C2H4O
- Short Name:
- J/A+A/402/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Cyclopropenylidene C_3_H_2_ and ethylene oxide C_2_H_4_O molecules are of astronomical importance as their observed lines, distributed throughout the observable microwave region, have a number of pairs having nearly equal frequencies, but different excitation energies and/or belonging to two different species of the molecule. Hence, these molecules may play important role in detecting physical conditions in cosmic objects. Therefore, in order to calculate intensities of the lines, we have investigated transfer of radiation through a cosmic object containing the molecule at a kinetic temperature of 10K. Our results show that some lines of the molecule may be found in absorption against the cosmic 2.7K background.
- ID:
- ivo://CDS.VizieR/J/A+AS/114/175
- Title:
- Einstein A-coefficients in CS transitions
- Short Name:
- J/A+AS/114/175
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Einstein A-coefficients for vib-rotational transitions in CS isotopomers, for vibrational quantum number v up to 20, rotational quantum number J up to 140, and {DELTA}v up to 4, are calculated. The change in J is governed by the selection rules {DELTA}J=+/-1. These coefficients play an important role in astronomy, as CS has been observed in a number of astronomical object.
- ID:
- ivo://CDS.VizieR/J/A+AS/131/137
- Title:
- Einstein A-Coefficients in SiC2 transitions
- Short Name:
- J/A+AS/131/137
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Einstein A-coefficients for the electric dipole transitions in Silicon Dicarbide molecule and its isotopomers between rotational levels of the ground vibrational state up to 51cm^-1^ are calculated. These coefficients are used for computing radiative life times of the levels. The A-coefficients are one of the important input parameters for the radiative transfer calculations.
- ID:
- ivo://CDS.VizieR/J/A+AS/117/557
- Title:
- Einstein coefficients for CO transitions
- Short Name:
- J/A+AS/117/557
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Einstein A-coefficients for vib-rotational transitions in CO isotopomers, for vibrational quantum number v up to 20, rotational quantum number J up to 140, and {DELTA}v up to 4, are calculated. The change in J is governed by the selection rules {DELTA}J=+/-1. These coefficients play an important role in astronomy, as CO is the most abundant molecule after H_2_, and has been observed in almost all the astronomical objects.
- ID:
- ivo://CDS.VizieR/J/ApJS/92/53
- Title:
- Einstein database of quasars. I.
- Short Name:
- J/ApJS/92/53
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first volume of the Einstein quasar database. The database includes estimates of the X-ray count rates, fluxes, and luminosities for 514 quasars and Seyfert 1 galaxies observed with the Imaging Proportional Counter (IPC) aboard the Einstein Observatory. All were previously known optically selected or radio-selected objects, and most were targets of the X-ray observations. The X-ray properties of the AGNs have been derived by reanalyzing the IPC data in a systematic manner to provide a uniform database for general use by the astronomical community. We use the database to extend earlier quasar luminosity studies which were made using only a subset of the currently available data. The database can be accessed on Internet via the SAO Einstein on-line system ("Einline") and is available in ASCII format on magnetic tape and DOS diskette.
4930. Einstein EMSS Survey
- ID:
- ivo://CDS.VizieR/IX/15
- Title:
- Einstein EMSS Survey
- Short Name:
- IX/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Einstein Extended Medium Sensitivity Survey (EMSS) consists of 835 serendipitous X-ray sources detected at or above 4 times the rms level in 1435 IPC fields with their centers located away from the galactic plane. Their limiting sensitivities range from ~5*10-14 to to ~ 3*10-12 erg.cm-2.s-1 in the 0.3-3.5keV band. A total area of 778 square degrees of the high galactic latitude sky (|b|>20) has been covered. The analysis has been performed using data from the Rev 1 processing system at the CfA. The resulting EMSS catalog is a flux-limited and homogeneous sample of astronomical objects that can be used for statistical studies. Here we present the table listing all the sources taken from the publication referenced below and the optical identifications. At present over 96% of the 835 X-ray sources have been successfully identified in the following proportions: active galactic nuclei (QSO's, quasars and Seyfert), 51.1%; BL Lacertae objects, 4.3%; clusters of galaxies, 12.2%; normal galaxies, 2.1%; cooling flow galaxies, 0.6%; Galactic stars 25.8%; and unidentified, 3.9%. Most of the individual optical counterparts are previously unknown objects and so constitute large statistical samples independent of previously selection methods. The contents of the table is described below. The sky coverage computed for a specific assumed source spectrum is also given under "Additional Information" below. For further details please see the published articles: Gioia et al. 1990, Stocke et al. 1991.