The Bose polaron problem: effect of mass imbalance on binding energy

By means of Quantum Monte Carlo methods we calculate the binding energy of an impurity immersed in a Bose-Einstein condensate at T = 0. The focus is on the attractive branch of the Bose polaron and on the role played by the mass imbalance between the impurity and the surrounding particles. For an impurity resonantly coupled to the bath, we investigate the dependence of the binding energy on the mass ratio and on the interaction strength within the medium. In particular, we determine the equation of state in the case of a static (infinite mass) impurity, where three-body correlations are irrelevant and the result is expected to be a universal function of the gas parameter. For the mass ratio corresponding to $^{40}$K impurities in a gas of $^{87}$Rb atoms we provide an explicit comparison with the experimental findings of a recent study carried out at JILA.Comment: 5 pages, 3 figure

The near-infrared spectrum of Mrk 1239: direct evidence of the dusty torus?

We report 0.8-4.5 micron SpeX spectroscopy of the narrow-line Seyfert 1 galaxy Mrk1239. The spectrum is outstanding because the nuclear continuum emission in the near-infrared is dominated by a strong bump of emission peaking at 2.2 micron, with a strength not reported before in an AGN. A comparison of the Mrk1239 spectrum to that of Ark564 allowed us to conclude that the continuum is strongly reddened by E(B-V)=0.54. The excess of emission, confirmed by aperture photometry and additional NIR spectroscopy, follows a simple blackbody curve at T=1200 K. This suggest that we may be observing direct evidence of dust heated near to the sublimation temperature, likely produced by the putative torus of the unification model. Although other alternatives are also plausible, the lack of star formation, the strong polarization and low extinction derived for the emission lines support the scenario where the hot dust is located between the narrow line region and the broad line region.Comment: 5 pages, 3 figures. Accepted to MNRAS letter

Hidden starburst in Seyfert 1 Galaxies

We report the detection of the 3.3 mu Polycyclic Aromatic Hydrocarbon (PAH) feature in two Seyfert 1 galaxies - NGC 3227 and Mrk 766, and one QSO - Mrk 478, observed with SpeX at IRTF at a spectral resolution not previously attained for this type of objects. Except for NGC 3227, this is the first time that the 3.3 mu PAH emission is detected in Mrk 766 and Mrk 478. The widths of the emission, reported also for the first time, are rather similar, ranging from 450 A to 550 A. The luminosity of the 3.3 mu PAH emission measured in the QSO Mrk 478 places it at a level similar of that found in starburst and infrared luminous galaxies and implies that this object is having a vigorous burst of star formation. The spatial resolution of the spectra allows us to constrain the location of the star-forming region to the inner 1 Kpc for the QSO and 150 pc for the Seyferts. Our results support the idea that these objects resides in molecular gas-rich galaxies and that their observed infrared excess is primarily due to star formation, as previously indicated by CO and H_2 observations. We also report, for Mrk 1239, the presence of a broad emission feature centred at 3.43 mu, not previosly detected in an extragalactic object and whose origin is not yet clear.Comment: 5 pages, 1 figure. Accepted to MNRAS pink page

The Near-Infrared Coronal Line Spectrum of 54 Nearby Active Galactic Nuclei

(Abridge) The relationship between coronal line (CL) emission and nuclear activity in active galactic nuclei (AGNs) is analyzed, for the first time, based on NIR spectra. The 8 CLs studied, of Si, S, Fe, Al and Ca elements and corresponding to ionization potentials (IP) in the range 125-450 eV, are detected in 67% (36 AGNs) of the sample. The four most frequent CLs - [SiVI] 19630\AA, [SVIII] 9913\AA, [SIX] 12520\AA\ and [SiX] 14320\AA, - display a narrow range in luminosity, with most lines located in the interval logL 39-40 erg/s. We found that the non-detection is largely associated with either a lost of spatial resolution or increasing object distance. Yet, there are AGNs where the lack of CLs may be genuine and reflect an AGN ionising continuum lacking photons below a few keV. The FWHM of the lines profiles increases with increasing IP up to energies around 300 eV, where a maximum in the FWHM is reached. For higher IP lines, the FWHM remains nearly constant or decreases with increasing IP. We ascribe this effect to an increasing density environment as we approach to the innermost regions of the AGN, where densities above the critical density of the CLs with IP larger than 300 eV are reached. This sets a strict range limit for the density in the boundary region between the narrow and the broad region of 10^8 - 10^9 cm^{-3}. A relationship between the luminosity of the coronal lines and that of the soft and hard X-ray emission and the soft X-ray photon index is observed: the coronal emission becomes stronger with both increasing x-ray emission (soft and hard) and steeper X-ray photon index. Thus, photoionization appears as the dominant excitation mechanism. These trends hold when considering Type 1 sources only; they get weaker or vanish when including Type 2 sources, very likely because the X-ray emission measured in the later is not the intrinsic ionising continuum.Comment: 44 pages, 16 figures. Accepted to Ap

Analisis Gaya Hidup Naomi Dalam Novel Chijin No Ai Karya Tanizaki Jun'ichirou Melalui Pendekatan Cultural Studies

Karya sastra merupakan gambaran dari kehidupan masyarakat. Sebagaimana gambaran masyarakat Jepang pada zaman Taisho yang mendapat pengaruh besar dari kebudayaan Barat sebagai akibat adanya restorasi Meiji. Besarnya pengaruh budaya Barat saat itu berakibat pada penerapan gaya hidup ala Barat yang menjadi populer bagi masyrakat Jepang khususnya pada zaman Taisho. Oleh karena itu, dalam penelitian kali ini penulis meneliti bagaimana dampak masuknya budaya Barat pada zaman Meiji yang tercermin pada penerapan gaya hidup tokoh utama dalam novel Chijin no Ai karya Tanizaki Jun'ichirou. Pada penelitian kali ini, penulis menggunakan pendekatan cultural studies yang berfokus pada pengaruh budaya Barat terhadap kehidupan masyarakat Jepang khususnya pada zaman Taisho. Dalam meneliti novel ini, penulis juga menggunakan teori postkolonial sebagai teori pendukung dalam menganalisis. Hasil penelitian kali ini menunjukkan bahwa dalam novel Chijin no Ai terdapat beberapa kutipan dialog tokoh utama yang menerapkan gaya hidup kebarat-baratan, dengan memakai baju Barat, mengkonsumsi makanan Barat serta bergaul dengan orang-orang Barat. Hal tersebut merupakan pengaruh budaya Barat yang menjadi populer pada zaman Taisho. Bagi peneliti selanjutnya yang ingin meneliti novel Chijin no Ai, dapat meneliti dengan menggunakan pendekatan struktural

Extended Coronal Emission Lines in Active Galactic Nuclei

VLT and NTT spectra are used to examine the nuclear and extended coronal line emission in a sample of well-known Seyfert 1 and 2 galaxies. The excellent spatial resolution obtained with VLT allowed us to map [SiVI] 1.963 $\mu$m and [SiVII] 2.48 $\mu$m on scales of up to 20 pc. Coronal line emission, extended to distances of $\sim$100 pc, is detected in some of the lines analyzed, particularly in [FeX] 6374\AA, [FeXI] 7891\AA, and [SiVII] 2.48$\mu$m. Most coronal lines are strongly asymmetric towards the blue and broader than low-ionization lines. This result is particularly important for Circinus, where previous observations had failed at detecting larger widths for high-ionization lines. Photoionization models are used to investigate the physical conditions and continuum luminosities necessary to produced the observed coronal emission. We found that an ionization parameter U> 0.10 is necessary to reproduce the observations, although the clouds should be located at distances < 30 pc.Comment: 4 pages, 6 figures, to appear in proceedings of IAU Symposium No. 222, The Interplay Among Black Holes, Stars and ISM in Galacti Nucle

Efektifitas Teknik Modeling Simbolis untuk Meningkatkan Motivasi Berprestasi Siswa SMP Negeri 2 Minasatene

The purpose of this research is (1) To determine student achievement motivation level overview of SMP Negeri 2 Minasatene, (2) To determine the effectiveness of modeling symbolic techniques in improving student achievement motivation SMP Negeri 2 Minasatene. This research is a quantitative research. kind of experiment in the form of One-group pretest-posttest design. The population is students of SMP Negeri 2 Minasatene and the sample size is 33 students. The technique of collecting using questionnaires, observation and documentation. The analysis using descriptive and inferential statistical t-test. The results showed that (1) The level of student achievement motivation SMP Negeri 2 Minasatene before being given a modeling symbolic techniques that are in the mean score of 99.18 are included in the high category and after being given the modeling symbolic techniques increases with the mean score of 105.88 which included the category of very high. This improvement can also be seen from the number of students who have a very high achievement motivation at the time before the application of symbolic modeling technique is 15 people, or approximately 45.5%, and after being given the modeling symbolic techniques increased to 24 people, or approximately 72.7%. (2) The value of 16.089 t count greater than 2.037 to 0.05 and received ttable research hypothesis which states " modeling symbolic technique is effective in improving student achievement motivation SMP Negeri 2 Minasatene"