English
Related papers

Related papers: A New Macho Search Strategy

200 papers

The LIGO-Virgo gravitational-wave (GW) observation unveiled the new population of black holes (BHs) that appears to have an extended mass spectrum up to around $70M_\odot$, much heavier than the previously-believed mass range ($\sim…

Astrophysics of Galaxies · Physics 2021-03-26 Satoshi Toki , Masahiro Takada

Gravitational microlensing has been employed to identify massive halo objects by their amplification of distant sources; MACHO searches have studied event times $2 h \lesssim t_0 \lesssim 2 y$ corresponding masses in the range $10^{-6}…

General Relativity and Quantum Cosmology · Physics 2008-12-27 Paul H. Frampton

We propose a new method to constrain the location of microlensing objects using EAGLE (Extremely Amplified Gravitational LEnsing) events. We have estimated the rate of EAGLE events by taking the finite-source effect in to account. We found…

Astrophysics · Physics 2009-10-31 Takahiro Sumi , Mareki Honma

In this article, we have investigated the possibility to distinguish between different galactic models through the microlensing parallax studies. We show that a systematic search for parallax effects can be done using the currently running…

Astrophysics · Physics 2007-05-23 S. Rahvar , M. Moniez , R. Ansari , O. Perdereau

We analyze the data of the gravitational microlensing survey carried out by by the MOA group during 2000 towards the Galactic Bulge (GB). Our observations are designed to detect efficiently high magnification events with faint source stars…

We present final results from the first phase of the EROS search for gravitational microlensing of stars in the Magellanic Clouds by unseen deflectors (machos: MAssive Compact Halo Objects). The search is sensitive to events with time…

The microlensing surveys MACHO, EROS, MOA and OGLE (hereafter called MEMO) have searched for microlensing toward the Large Magellanic Cloud for a cumulated duration of 27 years. We study the potential of joining these databases to search…

Astrophysics of Galaxies · Physics 2018-10-19 Arash Mirhosseini , Marc Moniez

We review recent gravitational microlensing results from the EROS, MACHO, and OGLE collaborations, and present some details of the very latest MACHO results toward the Galactic Bulge. The MACHO collaboration has now discovered in excess of…

Over the past decade, microlensing has developed into a powerful tool to study stellar astrophysics, especially stellar atmospheres, stellar masses, and binarity. I review this progress. Stellar atmospheres can be probed whenever the source…

Astrophysics · Physics 2016-08-30 Andrew Gould

Recently Sumi et al. (2011) reported evidence for a large population of planetary-mass objects (PMOs) that are either unbound or orbit host stars in orbits > 10 AU. Their result was deduced from the statistical distribution of durations of…

In this paper we investigate the properties of astrometric microlensing of distant radio sources (QSOs and radio galaxies) due to MACHOs, and discuss their implications for VERA (VLBI Exploration of Radio Astrometry). First we show that in…

Astrophysics · Physics 2015-06-24 Mareki Honma

Gravitational microlensing is a powerful method for discovering Isolated Stellar-Mass Black Holes(ISMBHs). These objects make long-duration microlensing events. To characterize these lensing objects by fully resolving the microlensing…

Astrophysics of Galaxies · Physics 2023-09-15 Sedighe Sajadian , Arya Mahmoudzadeh , Setareh Moein

Current microlensing searches calibrate the mass fraction of the Milky Way halo which is in the form of Massive Compact Halo Objects (MACHOs). We show that surveys like the Sloan Digital Sky Survey (SDSS) can probe the same quantity in…

Astrophysics · Physics 2009-10-30 Rosalba Perna , Abraham Loeb

Results are presented from the MACHO collaboration gravitational microlensing search. The experiment and the nearly 50 microlensing events that have been detected are described. Limits on the baryonic content of the halo are given, as are…

Using 7 years of MACHO survey data, we present a new determination of the optical depth to microlensing towards the Galactic bulge. We select the sample of 62 microlensing events (60 unique) on clump giant sources and perform a detailed…

We show that space-based microlensing experiments can recover lens masses and distances for a large fraction of all events (those with individual photometric errors <~ 0.01 mag) using a combination of one-dimensional microlens parallaxes…

Earth and Planetary Astrophysics · Physics 2015-06-18 Andrew Gould , Jennifer C. Yee

Microlensing events can be used to directly measure the masses of single field stars to a precision of $\sim$1-10\%. The majority of direct mass measurements for stellar and sub-stellar objects typically only come from observations of…

Solar and Stellar Astrophysics · Physics 2018-11-09 M. B. Nielsen , D. M. Bramich

We present preliminary results of the analysis of 5 years of MACHO data on the Galactic bulge microlensing events with clump giants as sources. In particular, we discuss: 1) the selection of `giant' events, 2) distribution of impact…

Of all planet-finding techniques, microlensing is potentially the most sensitive to Earth-mass planets. However, microlensing lightcurves generically yield only the planet-star mass ratio: the mass itself is uncertain to a factor of a few.…

Astrophysics · Physics 2009-11-07 Andrew Gould , B. Scott Gaudi , Cheongho Han

Following previous suggestions of other researchers, this paper discusses the prospects for astrometric observation of MACHO gravitational microlensing events. We derive the expected astrometric observables for a simple microlensing event…

Astrophysics · Physics 2009-10-30 A. F. Boden , M. Shao , D. Van Buren