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4131. Multi-wavelength study of clusters of galaxies. II.
ID:
ivo://CDS.VizieR/J/ApJ/761/114
Title:
Multi-wavelength study of clusters of galaxies. II.
Short Name:
J/ApJ/761/114
Date:
21 Oct 2021
Publisher:
CDS
Description:
Galaxy clusters provide powerful laboratories for the study of galaxy evolution, particularly the origin of correlations of morphology and star formation rate (SFR) with density. We construct visible to MIR spectral energy distributions of galaxies in eight low-redshift (z<0.3) clusters and use them to measure stellar masses and SFRs as a function of environment. A partial correlation analysis indicates that the SFRs of star-forming galaxies (SFGs) depend strongly on M_*_ (>99% confidence) with no dependence on R/R_200_ or projected local density at fixed mass. A merged sample of galaxies from the five best measured clusters shows <SFR>{prop.to}(R/R_200_)^1.1+/-0.3^ for galaxies with R/R_200_<=0.4. A decline in the fraction of SFGs toward the cluster center contributes most of this effect, but it is accompanied by a reduction in <SFR> for SFGs with R<=0.1R_200_. The increase in the fraction of SFGs toward larger R/R_200_ and the isolation of SFGs with reduced SFRs near the cluster center are consistent with the truncation of star formation by ram-pressure stripping, as is the tendency for more massive SFGs to have higher SFRs. We conclude that stripping is more likely than slower processes to drive the properties of SFGs with R<0.4R_200_ in clusters. We also find that galaxies near the cluster center are more massive than galaxies farther out in the cluster at ~3.5{sigma}, which suggests that dynamical relaxation significantly impacts the distribution of cluster galaxies as the clusters evolve.
4132. Multiwavelength study of Cyg OB2 5
ID:
ivo://CDS.VizieR/J/A+A/495/231
Title:
Multiwavelength study of Cyg OB2 5
Short Name:
J/A+A/495/231
Date:
21 Oct 2021
Publisher:
CDS
Description:
The properties of the early-type binary Cyg OB2 #5 have been debated for many years and spectroscopic and photometric investigations yielded conflicting results. We have attempted to constrain the physical properties of the binary by collecting new optical and X-ray observations. The optical light curves obtained with narrow-band continuum and line-bearing filters are analysed and compared. Optical spectra are used to map the location of the He II 4686 and H-alpha line-emission regions in velocity space. New XMM-Newton as well as archive X-ray spectra are analysed to search for variability and constrain the properties of the hot plasma in this system.
4133. Multiwavelength study of HII region S311
ID:
ivo://CDS.VizieR/J/MNRAS/461/2502
Title:
Multiwavelength study of HII region S311
Short Name:
J/MNRAS/461/2502
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a multiwavelength investigation of the young stellar population and star formation activities around the HII region Sharpless 311. Using our deep near-infrared observations and archival Spitzer-IRAC observations, we have detected a total of 125 young stellar objects (YSOs) in an area of ~86 arcmin^2^. The YSO sample includes eight Class I and 117 Class II candidate YSOs. The mass completeness of the identified YSO sample is estimated to be 1.0M_{sun}_. The ages and masses of the majority of the candidate YSOs are estimated to be in the range ~0.1-5Myr and ~0.3-6M_{sun}_, respectively. The 8um image of S311 displays an approximately spherical cavity around the ionizing source, which was possibly created by the expansion of the H ii region. The spatial distribution of the candidate YSOs reveals that a significant number of them are distributed systematically along the 8-{mu}m emission with a majority clustered around the eastern border of the HII region. Four clumps/compact HII regions are detected in the radio continuum observations at 1280MHz, which may have been formed during the expansion of the HII region. The estimated dynamical age of the region, main-sequence lifetime of the ionizing source, the spatial distribution and ages of the candidate YSOs indicate triggered star formation in the complex.
4134. Multiwavelength study of NGC 7419
ID:
ivo://CDS.VizieR/J/MNRAS/391/1279
Title:
Multiwavelength study of NGC 7419
Short Name:
J/MNRAS/391/1279
Date:
21 Oct 2021
Publisher:
CDS
Description:
Using new UBVRI H{alpha} CCD photometric observations and the archival infrared and X-ray data, we have carried out a multiwavelength study of a Perseus arm young open star cluster NGC 7419. Using XMM-Newton observations, we found several X-ray sources in the cluster region but none of the Herbig Ae/Be stars is detected in X-rays.
4135. Multiwavelength study of NGC 281 complex
ID:
ivo://CDS.VizieR/J/PASJ/64/107
Title:
Multiwavelength study of NGC 281 complex
Short Name:
J/PASJ/64/107
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a multiwavelength study of the NGC 281 complex, which contains the young cluster IC 1590 at the center, using deep wide-field optical UBVIc photometry, slitless spectroscopy along with archival data sets in the near-infrared (NIR) and X-ray regions.
4136. Multiwavelength study of RX J1117.4+0743
ID:
ivo://CDS.VizieR/J/ApJ/664/777
Title:
Multiwavelength study of RX J1117.4+0743
Short Name:
J/ApJ/664/777
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a multiwavelength study of the poor cluster RX J1117.4+0743 ([VMF98] 097) at z=0.485, based on GMOS/Gemini South g' and r' photometry and spectroscopy, and XMM-Newton observations. We examine its nature and surroundings by analyzing the projected galaxy distribution, the galaxy velocity distribution, the weak-lensing mass reconstruction, and the X-ray spectroscopy and imaging.
4137. Multiwavelength survey of HII regions in NGC 300
ID:
ivo://CDS.VizieR/J/ApJ/789/81
Title:
Multiwavelength survey of HII regions in NGC 300
Short Name:
J/ApJ/789/81
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of a galaxy-wide study of molecular gas and star formation in a sample of 76 H II regions in the nearby spiral galaxy NGC 300. We have measured the molecular gas at 250pc scales using pointed CO(J=2-1) observations with the Atacama Pathfinder Experiment telescope. We detect CO in 42 of our targets, deriving molecular gas masses ranging from our sensitivity limit of ~10^5^M_{sun}_ to 7x10^5^M_{sun}_. We find a clear decline in the CO detection rate with galactocentric distance, which we attribute primarily to the decreasing radial metallicity gradient in NGC 300. We combine Galaxy Evolution Explorer far-ultraviolet, Spitzer 24{mu}m, and H{alpha} narrowband imaging to measure the star formation activity in our sample. We have developed a new direct modeling approach for computing star formation rates (SFRs) that utilizes these data and population synthesis models to derive the masses and ages of the young stellar clusters associated with each of our H II region targets. We find a characteristic gas depletion time of 230Myr at 250pc scales in NGC 300, more similar to the results obtained for Milky Way giant molecular clouds than the longer (>2Gyr) global depletion times derived for entire galaxies and kiloparsec-sized regions within them. This difference is partially due to the fact that our study accounts for only the gas and stars within the youngest star-forming regions. We also note a large scatter in the NGC 300 SFR-molecular gas mass scaling relation that is furthermore consistent with the Milky Way cloud results. This scatter likely represents real differences in giant molecular cloud physical properties such as the dense gas fraction.
4138. Multi-wavelength variability of Mrk 421
ID:
ivo://CDS.VizieR/J/A+A/647/A88
Title:
Multi-wavelength variability of Mrk 421
Short Name:
J/A+A/647/A88
Date:
21 Oct 2021
Publisher:
CDS
Description:
The origin of the gamma-ray emission of the blazar Mrk 421 is still a matter of debate. We used 5.5 years of unbiased observing campaign data, obtained using the FACT telescope and the Fermi LAT detector at TeV and GeV energies, the longest and densest so far, together with contemporaneous multi-wavelength observations, to characterise the variability of Mrk 421 and to constrain the underlying physical mechanisms. We studied and correlated light curves obtained by ten different instruments and found two significant results. The TeV and X-ray light curves are very well correlated with a lag of <0.6 days. The GeV and radio (15GHz band) light curves are widely and strongly correlated. Variations of the GeV light curve lead those in the radio. Lepto-hadronic and purely hadronic models in the frame of shock acceleration predict proton acceleration or cooling timescales that are ruled out by the short variability timescales and delays observed in Mrk 421. Instead the observations match the predictions of leptonic models.
4139. Multiwavelength view of blazar PKS 2155-304
ID:
ivo://CDS.VizieR/J/A+A/539/A149
Title:
Multiwavelength view of blazar PKS 2155-304
Short Name:
J/A+A/539/A149
Date:
21 Oct 2021
Publisher:
CDS
Description:
Multiwavelength (MWL) observations of the blazar PKS 2155-304 during two weeks in July and August 2006, the period when two exceptional flares at very high energies (VHE, E>=100GeV) occurred, provide a detailed picture of the evolution of its emission. The complete data set from this campaign is presented, including observations in VHE gamma-rays (H.E.S.S.), X-rays (RXTE, CHANDRA, SWIFT XRT), optical (SWIFT UVOT, Bronberg, Watcher, ROTSE), and in the radio band (NRT, HartRAO, ATCA). Optical and radio light curves from 2004 to 2008 are compared to the available VHE data from this period, to put the 2006 campaign into the context of the long-term evolution of the source. The data set offers a close view of the evolution of the source on different time scales and yields new insights into the properties of the emission process. The predictions of synchrotron self-Compton (SSC) scenarios are compared to the MWL data, with the aim of describing the dominant features in the data down to the hour time scale. The spectral variability in the X-ray and VHE bands is explored and correlations between the integral fluxes at different wavelengths are evaluated. SSC modelling is used to interpret the general trends of the varying spectral energy distribution.
4140. 16{mu}m imaging around the HDF-N
ID:
ivo://CDS.VizieR/J/ApJ/634/128
Title:
16{mu}m imaging around the HDF-N
Short Name:
J/ApJ/634/128
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a pilot study of 16{mu}m imaging within the GOODS northern field. Observations were obtained using the "peak-up" imaging capability of the Spitzer IRS. We survey 35arcmin^2^ to an average 3{sigma} depth of 0.075mJy and detect 149 sources.