Interstellar dust and starlight are modeled for the galaxies of the project "Key Insights on Nearby Galaxies: A Far-Infrared Survey with Herschel." The galaxies were observed by the Infrared Array ...Camera and the Multiband Imaging Photometer for Spitzer on Spitzer Space Telescope, and the Photodetector Array Camera and Spectrometer and the Spectral and Photometric Imaging Receiver on Herschel Space Observatory. With data from 3.6 to 500 m, dust models are strongly constrained. Using a physical dust model, for each pixel in each galaxy we estimate (1) dust surface density, (2) dust mass fraction in polycyclic aromatic hydrocarbons (PAHs), (3) distribution of starlight intensities heating the dust, (4) total infrared (IR) luminosity emitted by the dust, and (5) IR luminosity originating in subregions with high starlight intensity. The dust models successfully reproduce the observed global and resolved spectral energy distributions. With the angular resolution of Herschel, we obtain well-resolved maps (available online) for the dust properties. As in previous studies, we find the PAH fraction to be an increasing function of metallicity, with a threshold oxygen abundance Z/Z 0.1, but we find the data to be fitted best with increasing linearly with above a threshold value of 0.15(O/H) . We obtain total dust masses for each galaxy by summing the dust mass over the individual map pixels; these "resolved" dust masses are consistent with the masses inferred from a model fit to the global photometry. The global dust-to-gas ratios obtained from this study are found to correlate with galaxy metallicities. Systems with Z/Z 0.5 have most of their refractory elements locked up in dust, whereas in systems with Z/Z 0.3 most of these elements tend to remain in the gas phase. Within galaxies, we find that is suppressed in regions with unusually warm dust with . With knowledge of one long-wavelength flux density ratio (e.g., f160/f500), the minimum starlight intensity heating the dust ( ) can be estimated to within ∼50%, despite a variation in of more than two orders of magnitude. For the adopted dust model, dust masses can be estimated to within ∼0.2 dex accuracy using the f160/f500 flux ratio and the integrated dust luminosity, and to ∼0.07 dex accuracy using the 500 m luminosity alone. There are additional systematic errors arising from the choice of dust model, but these are hard to estimate. These calibrated prescriptions for estimating starlight heating intensity and dust mass may be useful for studies of high-redshift galaxies.
•The ultrasound can release of bioactive compounds of the crystallized matrix of honey.•Some honeys liquefied with ultrasound showed increases in the bioactive compounds.•The treatment with ...ultrasound increased inhibitory effect against S.Typhimurium in some honeys.
The effect of ultrasound on the crystal size, phenols, flavonoids, Maillard products and antibacterial activity of crystallized honeys was studied. Three multifloral honeys (M), one monofloral (MO) and one honeydew (HD) honey were used. Ultrasound was performed at 42 kHz for different times (0, 5, 10 and 15 min). The antibacterial activities were tested against Salmonella typhimurium, Bacillus subtilis, Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus aureus and Escherichia coli. In all honeys, the parameters analyzed had significant differences ((P < 0.05)). After 15 min of ultrasound the HD had increments of 44 mg of gallic acid/100 g of honey in phenols, and some M showed increase in flavonoids (5.64 mg of quercitin /100 g of honey) and improvement in inhibition against Salmonella typhimurium was 13.1%. In some honeys the correlation between phenols or flavonoids and antibacterial activity were significant ((P < 0.05)). No correlation was found between Maillard products and antibacterial activity. The ultrasound treatment effect on the crystal size, phenols, flavonoid, Maillard products, and antibacterial activity of crystallized honeys were different in each honey.
The luminous Type IIn SN 2010jl shows strong signs of interaction between the SN ejecta and dense circumstellar material. Dust may be present in the unshocked ejecta; the cool, dense shell (CDS) ...between the shocks in the interaction region; or in the circumstellar medium (CSM). We present and model new optical and infrared photometry and spectroscopy of SN 2010jl from 82 to 1367 days since explosion. We evaluate the photometric and spectroscopic evolution using the radiative transfer codes mocassin and damocles, respectively. We propose an interaction scenario and investigate the resulting dust formation scenarios and dust masses. We find that SN 2010jl has been continuously forming dust based on the evolution of its infrared emission and optical spectra. There is evidence for preexisting dust in the CSM as well as new dust formation in the CDS and/or ejecta. We estimate that 0.005-0.01 M of predominantly carbon dust grains has formed in SN 2010jl by ∼1400 days post-outburst.
New far-infrared and submillimeter photometry from the Herschel Space Observatory is presented for 61 nearby galaxies from the Key Insights on Nearby Galaxies: A Far-Infrared Survey with Herschel ...(KINGFISH) sample. The spatially integrated fluxes are largely consistent with expectations based on Spitzer far-infrared photometry and extrapolations to longer wavelengths using popular dust emission models. Dwarf irregular galaxies are notable exceptions, as already noted by other authors, as their 500 mu m emission shows evidence for a submillimeter excess. In addition, the fraction of dust heating attributed to intense radiation fields associated with photodissociation regions is found to be (21 + or - 4)% larger when Herschel data are included in the analysis. Dust masses obtained from the dust emission models of Draine & Li are found to be on average nearly a factor of two higher than those based on single-temperature modified blackbodies, as single blackbody curves do not capture the full range of dust temperatures inherent to any galaxy. The discrepancy is largest for galaxies exhibiting the coolest far-infrared colors.
SN 2011ja was a bright (I = −18.3) Type II supernova occurring in the nearby edge on spiral galaxy NGC 4945. Flat-topped and multipeaked H α and H β spectral emission lines appear between 64 and 84 d ...post-explosion, indicating interaction with a disc-like circumstellar medium inclined ∼45° from edge-on. After day 84, an increase in the H- and K-band flux along with heavy attenuation of the red wing of the emission lines are strong indications of early dust formation, likely located in the cool dense shell created between the forward shock of the SN ejecta and the reverse shock created as the ejecta plows into the existing circumstellar material. Radiative transfer modelling reveals both ≈1 × 10−5 M⊙ of pre-existing dust located ∼1016.7 cm away and up to ≈6 × 10−4 M⊙ of newly formed dust. Spectral observations after 1.5 yr reveal the possibility that the fading SN is located within a young (3–6 Myr) massive stellar cluster, which when combined with tentative 56Ni mass estimates of 0.2 M⊙ may indicate a massive (≥25 M⊙) progenitor for SN 2011ja.
Lactobacillus rhamnosus cultured in sweet whey and harvested in the late log phase was entrapped in the inner aqueous phase of a double water-in-oil-in-water emulsion using concentrated sweet whey as ...emulsifier. The primary and double emulsion droplets showed practically no changes in their morphology and droplet size with aging time. The viability of the entrapped
L. rhamnosus in the double emulsion was compared to that of non-entrapped control cells exposed to low pH and bile salt conditions. The viability of the control cells (initial number
=
6.57
±
0.3
log
cfu
ml
−1) decreased significantly under low pH and bile salt conditions, and their survival was 71% and 89%, respectively. The survival of the entrapped cells (initial number
=
6.74
±
0.2
log cfu ml
−1) increased significantly under low pH and bile salt conditions, and their survival was 108% and 128%, respectively. It is concluded that the double emulsion protected
L. rhamnosus against simulated gastrointestinal tract conditions.
We report the first detection of the S(1) pure rotational line of ortho-H2 at 17.04 μm in an asymptotic giant branch star, using observations of IRC+10216 with the Echelon-cross-echelle Spectrograph ...(EXES) mounted on the Stratospheric Observatory for Infrared Astronomy. This line, which was observed in a very high-sensitivity spectrum (rms noise ≃0.04% of the continuum), was detected in the wing of a strong telluric line and displayed a P Cygni profile. The spectral ranges around the frequencies of the S(5) and S(7) ortho-H2 transitions were observed as well but no feature was detected in spectra with sensitivities of 0.12% and 0.09% regarding the continuum emission, respectively. We used a radiation transfer code to model these three lines and derived a mass-loss rate of (2.43 ± 0.21) × 10−5 M⊙ yr−1 without using the CO abundance. The comparison of this rate with previous estimates derived from CO observations suggests that the CO abundance relative to H2 is (6.7 ± 1.4) × 10−4. From this quantity and previously reported molecular abundances, we estimate the O/H and C/H ratios to be (3.3 ± 0.7) × 10−4 and >(5.2 ± 0.9) × 10−4, respectively. The C/O ratio is >1.5 ± 0.4. The absence of the S(5) and S(7) lines of ortho-H2 in our observations can be explained by the opacity of hot dust within 5 R⋆ from the center of the star. We estimate the intensity of the S(0) and S(2) lines of para-H2 to be ≃0.1% and 0.2% of the continuum, respectively, which are below the detection limit of EXES.
ABSTRACT
We present an analysis of the evolution of circumstellar dust and molecules in the environment of the very late thermal pulse object V4334 Sgr (Sakurai’s object) over an ∼20-yr period, ...drawing on ground-, airborne-, and space-based infrared photometry and spectroscopy. The dust emission, which started in 1997, resembles a blackbody that cooled from ∼1200 K in 1998 August to ∼180 K in 2016 July. The dust mass, assuming amorphous carbon, was ∼5 × 10−10 M⊙ in 1998 August, and we estimate that the total dust mass was ∼2 × 10−5 M⊙ by ∼2016. The appearance of a near-infrared excess in 2008 suggests that a new episode of (or renewed) mass-loss began then. We infer lower limits on the bolometric luminosity of the embedded star from that of the dust shell, which rose to ∼16 000 L⊙ before declining to ∼3000 L⊙. There is evidence for weak 6–7 μm absorption, which we attribute to hydrogenated amorphous carbon formed in material ejected by Sakurai’s object during a mass ejection phase that preceded the 1997 event. We detect small hydrocarbon and other molecules in the spectra, and trace the column densities in hydrogen cyanide (HCN) and acetylene (C2H2). We use the former to determine the 12C/13C ratio to be 6.4 ± 0.7, 14 times smaller than the Solar system value.
We report on the detection of hot CO
in the O-rich AGB star R Leo based on high spectral resolution observations in the range 12.8 - 14.3
m carried out with the Echelon-cross-Echelle Spectrograph ...(EXES) mounted on the Stratospheric Observatory for Infrared Astronomy (SOFIA). We have found ≃ 240 CO
emission lines in several vibrational bands. These detections were possible thanks to a favorable Doppler shift that allowed us to avoid contamination by telluric CO
features. The highest excitation lines involve levels at an energy of ≃ 7000 K. The detected lines are narrow (average deconvolved width ≃ 2.5 km s
) and weak (usually ≲ 10% the continuum). A ro-vibrational diagram shows that there are three different populations, warm, hot, and very hot, with rotational temperatures of ≃ 550, 1150, and 1600 K, respectively. From this diagram, we derive a lower limit for the column density of ≃ 2.2 × 10
cm
. Further calculations based on a model of the R Leo envelope suggest that the total column density can be as large as 7 × 10
cm
and the abundance with respect to H
- 2.5 × 10
. The detected lines are probably formed due to de-excitation of CO
molecules from high energy vibrational states, which are essentially populated by the strong R Leo continuum at 2.7 and 4.2
m.
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