- ID:
- ivo://CDS.VizieR/J/A+A/568/A55
- Title:
- Supergiant fast X-ray transients monitoring
- Short Name:
- J/A+A/568/A55
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We perform the first high-sensitivity soft X-ray long-term monitoring with Swift/XRT of three relatively unexplored supergiant fast X-ray transients (SFXTs), IGR J08408-4503, IGR J16328-4726, and IGR J16465-4507, whose hard X-ray duty cycles are the lowest measured among the SFXT sample, and compare their properties with those of the prototypical SFXTs. The behaviour of J08408 and J16328 resembles that of other SFXTs, and it is characterized by a relatively high inactivity duty cycle (IDC) and pronounced dynamic range (DR) in the X-ray luminosity. Like the SFXT prototypes, J08408 shows two distinct populations of flares, the first one associated with the brightest outbursts (L_X_>=10^35-36^erg/s), the second one comprising less bright events with L_X_<=10^35^erg/s. This double-peaked distribution seems to be a ubiquitous feature of the extreme SFXTs. The lower DR of J16328 suggests it is an intermediate SFXT. We find J16465 is characterized by IDC~5% and DR~40, reminiscent of classical supergiant HMXBs. The duty cycles measured with XRT are found to be comparable with those reported previously by BAT and INTEGRAL, when the higher limiting sensitivities of these instruments are taken into account and sufficiently long observational campaigns are available. We prove that no clear correlation exists between the duty cycles of the SFXTs and their orbital periods, which makes it difficult to interpret the SFXT peculiar variability by only using arguments related to the properties of supergiant star winds. Our findings favour the idea that a correct interpretation of the SFXT phenomenology requires a mechanism to strongly reduce the mass accretion rate onto the compact object during most of its orbit around the companion, as proposed in a number of theoretical works.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/599/1049
- Title:
- Supergiant molecular complexes in the Antennae
- Short Name:
- J/ApJ/599/1049
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have used previously published observations of the CO emission from the Antennae (NGC 4038/4039) to study the detailed properties of the supergiant molecular complexes with the goal of understanding the formation of young massive star clusters.
- ID:
- ivo://CDS.VizieR/J/A+A/545/A99
- Title:
- 2 supergiants and 2 hypergiants radio spectra
- Short Name:
- J/A+A/545/A99
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Herschel/HIFI spectra observed towards two Red Supergiants (NML Cyg, Betelgeuse) and two Yellow Hypergiants (AFGL2343, IRC+10420). The data focus on various transitions of ^12^CO, ^13^CO, ortho- and para- water, as well as some other bonus lines such as SiO, OH or NH_3_.
18324. Supergiants in NGC 672
- ID:
- ivo://CDS.VizieR/J/AJ/112/2559
- Title:
- Supergiants in NGC 672
- Short Name:
- J/AJ/112/2559
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- V, R, and I CCD images are used to investigate the photometric properties and spatial distribution of supergiants in the nearby interacting galaxy NGC 672. Not counting stars imbedded in H II regions, our sample consists of 237 objects. The (V-R,V-I) two-color diagram indicates that the majority of these stars have spectral types between A-K. Statistical tests show that the outer region of NGC 672 contains a redder population of supergiants than the inner region. Comparisons with theoretical evolutionary tracks indicate that the majority of the supergiants in NGC 672 have progenitor masses between 15M_{sun}_ and 25M_{sun}_, and that the inner regions contain stars that are more massive than in the outer disk, indicating that an age gradient is present. The luminosity functions in all three bandpasses follow power laws, and the exponent in V=0.79+/-0.06, in good agreement with other galaxies. The brightest red supergiants occur at V~22.0, from which we derive a distance modulus of 29.5, corresponding to 7.9(+1.0)(-0.9)Mpc.
- ID:
- ivo://CDS.VizieR/J/ApJ/865/106
- Title:
- SUPER GOODS. III. ALMA data for SCUBA-2 sources
- Short Name:
- J/ApJ/865/106
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyze the >4{sigma} sources in the most sensitive 100arcmin^2^ area (rms<0.56mJy) of a SCUBA-2 850{mu}m survey of the GOODS-S and present the 75 band-7 ALMA sources (>4.5{sigma}) obtained from high-resolution interferometric follow-up observations. The raw SCUBA-2 >4{sigma} limit is fainter than 2.25mJy throughout this region, and deboosting corrections would lower this further. Of the 53 SCUBA-2 sources in this sample, only five have no ALMA detections, while 13% (68% confidence range 7%-19%) have multiple ALMA counterparts. Color-based high-redshift dusty galaxy selection techniques find at most 55% of the total ALMA sample. In addition to using literature spectroscopic and optical/near-infrared photometric redshifts, we estimate far infrared photometric redshifts based on an Arp 220 template. We identify seven z>~4 candidates. We see the expected decline with redshift of the 4.5 and 24{mu}m to 850{mu}m flux ratios, confirming these as good diagnostics of z>~4 candidates. We visually classify 52 ALMA sources, finding 44% (68% confidence range 35%-53%) to be apparent mergers. We calculate rest-frame 2-8keV and 8-28keV luminosities using the 7Ms Chandra X-ray image. Nearly all of the ALMA sources detected at 0.5-2keV are consistent with a known X-ray luminosity to 850{mu}m flux relation for star-forming galaxies, while most of those detected at 2-7keV are moderate-luminosity AGNs that lie just above the 2-7keV detection threshold. The latter largely have substantial obscurations of logN_H_=23-24cm^-2^, but two of the high-redshift candidates may even be Compton thick.
- ID:
- ivo://CDS.VizieR/J/ApJ/837/139
- Title:
- SUPER GOODS. I. Ultradeep SCUBA-2 survey
- Short Name:
- J/ApJ/837/139
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this first paper in the SUPER GOODS series on powerfully star-forming galaxies in the two GOODS fields, we present a deep SCUBA-2 survey of the GOODS-N at both 850 and 450{mu}m (central rms noise of 0.28mJy and 2.6mJy, respectively). In the central region, the 850{mu}m observations cover the GOODS-N to near the confusion limit of ~1.65mJy, while over a wider 450arcmin^2^ region-well complemented by Herschel far-infrared imaging-they have a median 4{sigma} limit of 3.5mJy. We present >=4{sigma} catalogs of 186 850{mu}m and 31 450{mu}m selected sources. We use interferometric observations from the Submillimeter Array (SMA) and the Karl G. Jansky Very Large Array (VLA) to obtain precise positions for 114 SCUBA-2 sources (28 from the SMA, all of which are also VLA sources). We present new spectroscopic redshifts and include all existing spectroscopic or photometric redshifts. We also compare redshifts estimated using the 20cm/850{mu}m and the 250cm/850{mu}m flux ratios. We show that the redshift distribution increases with increasing flux, and we parameterize the dependence. We compute the star formation history and the star formation rate (SFR) density distribution functions in various redshift intervals, finding that they reach a peak at z=2-3 before dropping to higher redshifts. We show that the number density per unit volume of SFR>~500M_{sun}_/yr galaxies measured from the SCUBA-2 sample does not change much relative to that of lower SFR galaxies from UV selected samples over z=2-5, suggesting that, apart from changes in the normalization, the shape in the number density as a function of SFR is invariant over this redshift interval.
- ID:
- ivo://CDS.VizieR/J/ApJ/887/23
- Title:
- SUPER GOODS. IV. 850um data of CDFS X-ray sources
- Short Name:
- J/ApJ/887/23
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Chandra Deep Field (CDF)-S is the deepest X-ray image available and will remain so for the near future. We provide a spectroscopic (64.5%; 64% with spectral classifications) and photometric redshift catalog for the full 7Ms sample, but much of our analysis focuses on the central (off-axis angles <5.7') region, which contains a large, faint ALMA sample of 75 >4.5{sigma} 850{mu}m sources. We measure the 850{mu}m fluxes at the X-ray positions using the ALMA images, where available, or an ultradeep SCUBA-2 map. We find that the full X-ray sample produces ~10% of the 850{mu}m extragalactic background light. We separate the submillimeter-detected X-ray sources into star-forming galaxies and active galactic nuclei (AGNs) using a star formation rate (SFR) versus X-ray luminosity calibration for high-SFR galaxies. We confirm this separation using the X-ray photon indices. We measure the X-ray fluxes at the accurate positions of the 75 ALMA sources and detect 70% at >3{sigma} in either the 0.5-2 or 2-7keV bands. However, many of these may produce both their X-ray and submillimeter emission by star formation. Indeed, we find that only 20% of the ALMA sources have intermediate X-ray luminosities (rest-frame 8-28 keV luminosities of 10^42.5^-10^44^erg/s), and none has a high X-ray luminosity (>10^44^erg/s). Conversely, after combining the CDF-S with the CDF-N, we find extreme star formation (SFR>300M_{sun}_/yr) in some intermediate X-ray luminosity sources but not in any high X-ray luminosity sources. We argue that the quenching of star formation in the most luminous AGNs may be a consequence of the clearing of gas in these sources.
- ID:
- ivo://CDS.VizieR/J/PASJ/68/65
- Title:
- Superhumps in SU UMa-type dwarf novae
- Short Name:
- J/PASJ/68/65
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Continuing the project described by Kato et al. (2009PASJ...61S.395K), we collected times of superhump maxima for 128 SU UMa-type dwarf novae observed mainly during the 2015-2016 season and characterized these objects. The data have improved the distribution of orbital periods, the relation between the orbital period and the variation of superhumps, and the relation between period variations and the rebrightening type in WZ Sge-type objects. Coupled with new measurements of mass ratios using growing stages of superhumps, we now have a clearer and statistically greatly improved evolutionary path near the terminal stage of evolution of cataclysmic variables. Three objects (V452 Cas, KK Tel, and ASASSN-15cl) appear to have slowly growing superhumps, which is proposed to reflect the slow growth of the 3 : 1 resonance near the stability border. ASASSN-15sl, ASASSN-15ux, SDSS J074859.55+312512.6, and CRTS J200331.3-284941 are newly identified eclipsing SU UMa-type (or WZ Sge-type) dwarf novae. ASASSN-15cy has a short (~0.050d) superhump period and appears to belong to EI Psc-type objects with compact secondaries having an evolved core. ASASSN-15gn, ASASSN-15hn, ASASSN-15kh, and ASASSN-16bu are candidate period bouncers with superhump periods longer than 0.06d. We have newly obtained superhump periods for 79 objects and 13 orbital periods, including periods from early superhumps. In order that future observations will be more astrophysically beneficial and rewarding to observers, we propose guidelines on how to organize observations of various superoutbursts.
- ID:
- ivo://CDS.VizieR/J/PASJ/69/75
- Title:
- Superhumps in SU UMa-type dwarf novae
- Short Name:
- J/PASJ/69/75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Continuing the project described by Kato et al. (2009PASJ...61S.395K), we collected times of superhump maxima for 127 SU UMa-type dwarf novae observed mainly during the 2016-2017 season and characterized these objects. We provide updated statistics of the relation between the orbital period and the variation of superhumps, the relation between period variations and the rebrightening type in WZ Sge-type objects. We obtained the period minimum of 0.05290(2)d and confirmed the presence of the period gap above the orbital period ~0.09d. We note that four objects (NY Her, 1RXS J161659.5+620014, CRTS J033349.8-282244, and SDSS J153015.04+094946.3) have supercycles shorter than 100d but show infrequent normal outbursts. We consider that these objects are similar to V503 Cyg, whose normal outbursts are likely suppressed by a disk tilt. These four objects are excellent candidates to search for negative superhumps. DDE 48 appears to be a member of ER UMa-type dwarf novae. We identified a new eclipsing SU UMa-type object, MASTER OT J220559.40-341434.9. We observed 21 WZ Sge-type dwarf novae during this interval and report 18 of them in this paper. Among them, ASASSN-16js is a good candidate for a period bouncer. ASASSN-16ia showed a precursor outburst for the first time in a WZ Sge-type superoutburst. ASASSN-16kg, CRTS J000130.5+050624, and SDSS J113551.09+532246.2 are located in the period gap. We have newly obtained 15 orbital periods, including periods from early superhumps.
18330. Superluminal motion in AGN
- ID:
- ivo://CDS.VizieR/J/other/ChJAA/8.385
- Title:
- Superluminal motion in AGN
- Short Name:
- J/other/ChJAA/8.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have collected an up-to-date sample of 123 superluminal sources (84 quasars, 27 BL Lac objects and 12 galaxies) and calculated the apparent velocities ({beta}_app_) for 224 components in the sources with the {Lambda}-CDM model. We checked the relationships between their proper motions, redshifts, {beta}_app_ and 5GHz flux densities. Our analysis shows that the radio emission is strongly boosted by the Doppler effect. The superluminal motion and the relativistic beaming boosting effect are, to some extent, the same in active galactic nuclei.